Uploaded files to Assistant API randomly fail with "file not accessible with tool" when referenced

I’m uploading files (tried PDFs and TXT) using files.create then referencing the file ID in threads.create along with my message. My assistant should analyze the file and return results based on its knowledge and instructions, which it does but fails randomly with a variation of error messages (which also seem random) such as “Can’t interact with file” or “I see files have been uploaded but I can’t access them” or even “I apologize, but it seems there may have been a mix-up as I received multiple notifications of files being uploaded without being able to access them through my browser tool.”

Thinking maybe it’s a caching issue on their end but I’ve tried adding a wait before calling each thread as well as doing a files.retrieve to get the status (should show as “processed”) before creating a new thread but to no avail. I would say it fails about 80% of the time.

Has anyone else experienced this? Any workarounds?

Edit: Seems to happen in the Playground too.