Why are Custom-GPTs not working

I created a custom GPT to program a Webapp. In my Knowledgebase I have several .txt files, which include the Code I have already written. But suddenly, it tells me, that it is not able to access these files. Has anyone the same issue?

I do. And I have had it for several weeks now. It comes and goes.

I noticed yesterday that my personalized GPT gave me an answer from a fully separate chat session, that ended at least one week ago, unrelated to my initial prompt in the current session.
That occurred as I was assembling the GPT acting role in an unfinished prompt, and sending it unintentionally into a chat session.
Gpt answered with a response as I prompted with the document that exists in knowledge basis of my other personalized gpt.
I prompted a simple request with an occurred error, but Gpt responded in loop-like excusions.
The attached .txt file has been uploaded
via the desktop web version interface into, as I wrote, fully another personalized gpt.
I have tried to update those gpts but it failed to update one of them, without figuring out why after shorter checkingsā€¦
![Screenshot_2024-04-15-00-20-54-160_com.openai.chatgpt|225x500]