Chat history disappeared / GPTs no longer working

Hi,

I have a groups account with a couple of members. I use one of the accounts for support in work-related info tasks. Since yesterday, I could access this account without any problems at my workplace. However, since today my chat history disappeared (“Unable to load history”) and the chat functionality factually stopped.

I know that this issue has been addressed several times in several forums. I could not find a working solution or explanation though. Any idea what could have caused it suddenly, and how to fix it?

/N