Same here!
Chrome on Win7 : 
Firefox on Win7: 
iOS :
Android :
Changing DNS to 1.1.1.1 and 8.8.8.8 as suggested in past threads on the same error did not help.
Update:
Firefox on Win7 works, but stragely I do still get the message
{“detail”:{“message”:“Unauthorized - Access token is missing”}}
when calling https://chatgpt.com/backend-api/compliance
which seems to handle the Oauth info according to this post