I can chat with gpt before log in, but can not after

I am a plus user. When I started uploading a document on 4o yesterday, the arrow turned gray and the conversation did not start. I waited for a long time but there was no response. I switched networks and browsers and cleared all cookies, but nothing worked. But when I logged out, I could talk to 4o normally. Once I logged in, I could not chat. Why is this?