ChatGPT conversation messages disappeared

ChatGPT Bugs
1

Environment

  • Surface: Web / macOS
  • Browser or app version: Safari 26.0
  • Affected feature and model, if relevant: ChatGPT conversation history / in-thread message loading; GPT-5.6

Bug

A substantial portion of messages from an existing ChatGPT conversation suddenly became unavailable from the in-thread transcript.

The conversation itself still exists and I can continue sending new messages, but a large section of previously visible messages is no longer accessible. I did not delete or archive the conversation or those messages.

Expected behavior: All previously sent messages in an existing conversation should remain accessible when reopening and continuing the conversation.

Actual behavior: Older messages within the conversation are missing while the conversation itself remains active.

This is particularly problematic because the missing messages contained important work and context from a long-running session.

Conversation URL:

Reproduction

  1. Open the affected ChatGPT conversation using the URL above.
  2. Scroll back through the conversation to the earlier messages.
  3. A substantial portion of the previously available conversation is missing/inaccessible.
  4. New messages can still be sent in the same conversation.
  5. The conversation itself has not been deleted or archived.
  6. The issue appears to affect the in-thread conversation history rather than the conversation disappearing from the sidebar.

Diagnostics

Exact error or screenshot:
No explicit error message is displayed. Earlier messages simply fail to appear in the conversation. Screenshot attached showing the affected ChatGPT session.

When it happened (with timezone) and how often:
September 23, 2026, approximately 1:00 PM IST (UTC+5:30). The issue was noticed during an active conversation and persisted afterward.

The affected conversation contains a large amount of previously completed work, so recovering or investigating the missing messages is important.

2

Have exactly the same issue on my account.

I’m seeing what appears to be the same issue today with a long-running important ChatGPT conversation. A substantial block of previously visible messages disappeared from within the conversation, while the conversation itself remained present.

I reproduced the problem across different devices/sessions, and on one device opening the affected conversation repeatedly produced “Network connection lost. Attempting to reconnect…”.

I have requested a full OpenAI data export to determine whether the missing messages are still present in the underlying conversation data.

3

I’ve also lost important work twice now since the update. It happens when ChatGPT switches me from Instant to Work mode mid Chat. I am unable to retrieve anything past that point when returning to work.

This occurs across platforms – macOS, iOS, browser (Firefox) or desktop app

I’ve posted on Sep 16 as: “Missing Work chats: one stops at the Work handoff, another has disappeared” tagged as a Bug.

Does anyone know how support works for ChatGPT?