GPT-5.6 Sol High Reasoning Appears Broken — Instant Replies, No Deep Thinking, File Workflows Failing

Since August 1st 2026 , My Plus account is working as a joke . I want to report a serious reliability issue with GPT-5.6 Sol High mode and ask other developers/users if they are experiencing the same behavior.

I use ChatGPT for complex full-stack development workflows, including large files, code analysis, debugging, architecture planning, and multi-step execution.

Before this issue appeared, GPT-5.6 Sol High could properly handle long-running tasks. Some workflows would continue processing for 60–100+ minutes, reading files, analyzing context, planning solutions, and gradually completing the requested work.

Recently, the behavior has changed completely.

Current symptoms:

  • GPT-5.6 Sol shows High reasoning mode, but replies almost instantly.
  • The model appears to skip the actual thinking/reasoning process.
  • Complex tasks are not executed properly.
  • Uploaded files successfully complete upload, but the model often does not actually read or analyze them.
  • Long-context workflows fail.
  • Multi-step development tasks stop before execution begins.
  • The model gives short generic answers instead of performing the requested work.

From a software engineering perspective, this looks like a backend pipeline issue rather than a simple quality change.

Possible affected areas:

  • Model routing
  • Reasoning budget allocation
  • File retrieval pipeline
  • Context window processing
  • Execution/runtime workers
  • Tool orchestration

The most concerning part is that the UI indicates High reasoning, but the actual behavior feels closer to a fast response mode.

Example workflow:

  1. Upload project ZIP/file → upload succeeds.
  2. Select GPT-5.6 Sol High.
  3. Give detailed development instructions.
  4. Previously: model analyzed files and performed the workflow.
  5. Now: model responds within seconds without completing the task.

This has effectively stopped my development workflow.

Questions for the community:

  1. Is anyone else experiencing GPT-5.6 Sol High responding instantly despite selecting High reasoning?
  2. Are uploaded files failing to be read after successful upload?
  3. Did your previous long-running workflows suddenly become much shorter and incomplete?
  4. Has OpenAI acknowledged any ongoing regression related to GPT-5.6 reasoning, routing, or file processing?

If this is a known issue, can OpenAI provide an update on:

  • current investigation status,
  • affected users/plans,
  • expected resolution timeline?

I would appreciate confirmation from other developers experiencing the same regression.

Its been broken for the past two weeks I have not used chatgpt because its been broken

And im a pro member too that what makes it worse many plus and pro members been having the same issues

The issue has been raised at least 2 weeks before. I’m skill using business plan and same error has been made on my side.

Yeah I dont know if all these issues are because they are preparing for astra because these issues are very familiar before 5.6 sol came out 5.5 faced similar issues for the past two weeks before 5.6 released and that was most likely due to OpenAI preparing there infrastructure and servers for 5.6 so sll of these issues over the last two weeks seems most likely due to OpenAI preparing chatgpt for astra but I just hope that OpenAI fixes all of the issues first before releasing astra I made posts about all of the issues Why is GPT-5.6 failing long-context tasks? - #33 by LL01344

Yes exactly

I made a similar post in 1 September

Since 20 August it was happening back and forth, been fixed for like 4 days but problem again appeared on 1 September and has not fixed yet

If you check the request and slugs , you can see that it is actually 5.5 mini that is resolving your request which is why it feel super unhelpful and useless with dumb responses

This is considered some kind of robbery when we have been promised to have unlimited core chat with flagship models

I think I WON’T renew my subscription

I was a plus user for over 6 months straight

I completely agree. Since August 20th, it has been working terribly. Sometimes it identifies itself as GPT-5.5 mini, and now it says it is Sol, but it cannot even handle basic tasks anymore. It constantly ignores the context of the conversation, so it is obvious that this is not the same GPT-5.6 experience that was advertised.

It feels like the system is simply giving misleading information instead of acknowledging the problem. OpenAI seems to be avoiding the issue and closing discussions rather than actually fixing it.

I have already purchased three different accounts, and the problem is almost identical on all of them, including Plus and Pro plans. I will not renew my subscription. It makes more sense to switch to Claude than continue paying for a service that no longer works reliably.

OpenAI can keep claiming that they have fixed the issue and refuse to provide any real explanation, but even a simple observation makes the situation obvious: if you buy three different accounts and the same problem appears on all three of them, and at the same time many users are reporting identical issues, then the problem clearly exists.

It means they are simply unable to properly resolve it. Otherwise, how can completely new accounts have the same problems and supposed “violations” or limitations from the very beginning? That does not make sense if everything was actually fixed.

Yes. I’m a Pro user and I’m seeing a very similar regression, but in my case it goes far beyond High simply replying too quickly. I use ChatGPT for long-running technical project work involving large archives and source trees, code analysis, debugging, multi-step changes, rebuilding and validating project files, and creating downloadable outputs. For the past few weeks the reliability has been absolutely terrible across multiple completely unrelated Projects and conversations.

The Pro execution/runtime path itself also appears fundamentally broken for me. This is not just a case of the model giving weaker answers. Complex tasks that require sustained execution, inspecting files, modifying code, validating results, rebuilding outputs and then physically checking the resulting artifacts routinely fail somewhere in the middle. A task can make substantial real progress for tens of minutes or longer and then the execution layer simply dies.

When that happens, tools may stop returning usable results entirely, execution can time out, “Thinking Failed” or “Something went wrong” can appear, tool calls can stop completing, or the run can finish without the files or outputs it was supposed to create. In some cases even very simple sanity checks stop working once the execution path has failed. The conversation may still look alive and continue producing text, but the actual Pro execution environment behind it is effectively unusable.

I repeatedly get workflows that make real progress for tens of minutes or longer and then suddenly collapse with “Something went wrong”, “Thinking Failed”, “Connection interrupted”, message delivery timeouts, or other failures. I’ve also had the execution/tool channel die in the middle of real work: container/Python/tools stop returning usable results, trivial echo/print sanity checks fail, or the UI returns things like “Skipped 1 message” instead of the expected tool result. In other cases the Code Interpreter session expires, download status fails, or the conversation claims that files/results have been completed but a later physical check shows that the expected artifacts are simply not there.

File handling has also been unreliable. I’ve had newly uploaded ZIPs and other files visibly present in the conversation UI while the execution runtime could not access them at all. I’ve seen runs reach a supposed checkpoint and then become impossible to verify because the runtime is gone, which means I have to discard work and fall back to the last state I physically verified. This makes any serious multi-step development workflow extremely risky because I can’t trust that “completed” work is actually durable.

Tool routing/orchestration is broken for me as well. ChatGPT constantly triggers image generation during completely ordinary technical and text conversations where no image was requested — sometimes dozens of times a day and on particularly bad days close to a hundred times. Even after I stop it and explicitly say “DO NOT GENERATE AN IMAGE, JUST ANSWER IN TEXT”, it can immediately trigger the image tool again. The image usually does not even finish; the run collapses and I then get a noticeably shallower, worse text response, almost as if the request has fallen onto a much weaker execution path.

I’ve also had completely benign work routed into additional safety/processing states, frontend failures such as React #185, runs that claim work is continuing when it clearly is not, and inconsistent UI/backend states after reload.

I even had another fresh failure where my message appeared normally in the conversation, ChatGPT returned “Hmm…something seems to have gone wrong”, and after I reloaded the page my own message had disappeared from the conversation history as if it had never been sent.

Another major problem is that a failure late in a long technical run can invalidate the entire session. If the runtime dies after substantial work has supposedly been completed, I can no longer trust summaries such as “the files were created”, “the changes were applied”, or “validation passed” unless I can physically inspect the resulting files myself. I have already had situations where reported progress or completed outputs could no longer be verified after the execution environment failed. For serious development work, that is disastrous because the only safe option is often to throw away the unverified work and restart from the last known-good state.

The important part is that these failures are not confined to one old conversation, one project, one browser tab, or one type of task. I have reproduced different parts of this across unrelated technical projects and fresh conversations. Sometimes one part of ChatGPT still works while the execution/runtime path is completely broken, which makes this look much more like a broader reliability/routing/runtime problem than simply “the model got worse”.

I already have an open Support investigation and have sent them extensive screenshots, timestamps, conversation links, controlled comparisons, and examples from multiple projects. Support has confirmed that the issue remains unresolved and that the evidence is part of a technical investigation, but I still have not received a concrete technical status or explanation.

At this point I simply cannot trust ChatGPT Pro for serious development work. Every time I ask it to inspect files, make code changes, rebuild an archive, validate the result and give me the finished files, I have to assume that somewhere in the process the reasoning, runtime, file access, tool result channel, response delivery, or persistence layer may break and invalidate the work.

So for me this is not merely a quality regression in GPT-5.6 Sol High. The Pro execution environment itself has become unreliable to the point of being functionally broken for serious multi-step technical work.

I am a Plus user and I have started experiencing the same issue with 5.6 Sol in chat mode. Its responses are almost useless now. All it replies is what it will do to solve my problem but it never does. And when I reply by saying it to do it, it apologizes and says I should have done that, but still doesn’t work on my problem statement. When I switch to 5.5 it works perfectly. But why should I use an older model. How are you guys coping up with this ?

I’m experiencing a very similar issue in long-context Project conversations, including branched chats.

The behavior is highly inconsistent. For the same complex request, one attempt may produce a complete answer that conflicts with established context; another may reply almost instantly with only something like “I’ll follow your requirements” and then stop without doing the work. Regenerating the response may trigger several minutes of apparently genuine reasoning and produce a much better, context-aware answer, only for the output to be cut off halfway with “Error in message stream.”

I have also repeatedly encountered failures after a long task had already made real progress. The run may suddenly end with “Something went wrong,” “Thinking Failed,” a connection interruption, or a message delivery timeout. In file workflows, the model may describe what it intends to create or update but never actually produce the file. Simple read-only checks can still succeed, while longer synthesis, editing, or artifact-creation tasks fail unpredictably.

Seeing the same issue as SnappyBison27 today.

I’m seeing a similar issue with GPT-5.6 Sol High.

On multi-step tasks, especially ones involving files or tools, it sometimes responds almost immediately with a plan or summary instead of actually carrying out the work. I’ve also had messages fail to load and require resending.

The issue is not simply shorter answers—it feels like the deeper reasoning/execution phase is sometimes being skipped entirely despite High reasoning being selected.

More transparency around whether High reasoning was actually used, along with better reliability for file and tool workflows, would be very helpful.

I been testing 5.6 and its been working again for me I will keep doing tests the best thing I can say is keep posting the issues on the forums and send support emails to OpenAI that what I did I kept posting the issues on here and kept sending support emails to support but im continuing to test 5.6 to see if it stays consistent

i have similar problems,it looks like gpt send its thinking procedure instead the real answer

Yeah, I’m having the exact same issue in ChatGPT web. The model output quality is absolutely terrible, making it unusable. It doesn’t use tools or reason, and it doesn’t display the time it spent thinking above the response anymore, which is likely because it returns a response instantly. Sometimes it doesn’t even return an output.

What is strange is that is still identifies itself as 5.6 sol and in the network logs in Chrome dev tools it resolves the request as 5.6 sol as well. However, this is clearly impossible with the short, instant answers I’m getting with a terrible quality. There is clearly some sort of silent downgrading or issue on the backend that needs to be addressed by OpenAI.

This started yesterday for me so after the release of GPT 6 Astra.

I have tried contacting support but it is a pretty useless AI agent who’s fixes don’t work and then it simply states that the Open AI status page says all systems are operational.

If anyone has any idea how to fix this issue it would be great, an OpenAI really need to address the situation and have some transparency on what is going on, because at the end of the day the money being paid for the service is completely going to waste on some low quality model.

An update on my findings, using 5.6 Sol in ChatGPT web but on instant reasoning level produces higher quality of answer as I would have normally seen perviously, it is just medium and high levels that seem to be causing the issue right now.

UPDATE: I found a solution to the issue for the time being; if you simply click the try again button underneath the response, it seems to fix the issue. At least for me and some others I was discussing with, tried this and the model would reason through its answers and use its tools correctly again and provide a high quality of response.

Yesterday everything was still more or less okay, but today the model isn’t thinking at all… It doesn’t even pause to consider difficult problems; it just spits out the answer a second later, as if it were thinking at the “Instant” level.

The Try again fixes it observation is actually one of the more interesting clues in this thread.

I would be careful with one inference, though: a terrible instant response does not necessarily mean the request resolved to 5.5-mini. That routing bug has existed and can be confirmed from metadata when it happens, but I have also captured genuinely resolved GPT-5.6 turns that received materially different execution treatment.

In my own controls, a clean ordinary-Chat GPT-5.6 High/Extended turn could stay on a short foreground-style path and terminate unfinished around ~25–26m, while other current GPT-5.6 Extra High turns were admitted to a conversation-turn-* / worker/SAServer path and ran productively well past 30m. Separately, I have seen the mini-routing problem too. They are not the same defect.

That makes your first-response-vs-Try again comparison potentially useful: regeneration is a new turn/request, so it can plausibly receive a different backend treatment even though the visible conversation and selected model look unchanged.

If this reproduces naturally, the cleanest evidence would be to compare the first response and the regenerated response rather than only judging answer quality:

  • requested and resolved model slug for each;
  • reasoning effort;
  • visible thinking duration;
  • whether tools were actually called;
  • whether a stream_handoff / conversation-turn-* topic appears;
  • whether the useful retry has worker/SAServer markers that the instant first attempt lacks.

If both turns genuinely resolve to GPT-5.6 but only the retry receives the deeper execution path, that would be much stronger evidence than saying the first response merely “felt like mini.”

So I would keep two hypotheses separate here: wrong-model routing and correct-model / wrong execution treatment. Both can produce an instant, shallow-looking answer from the UI, but they require different fixes.

I am on the 200 USD plan.

This bug persists for me too.

I’m using GPT 6 pro and it keeps failing thinking/stopped thinking. When it finally works, it starts responding without thinking at all. I’m using two pro chats concurrently btw.

Frankly speaking, this is terrible.