Unable to communicate with iCloud with my iPad

Suddenly I can’t backup my iPad to iCloud and update or create folders in my iCloud. I signed out and back into my Apple ID twice & preformed a forced reset. Same problem, I still can’t communicate with my iCloud. I use iOS 15.1. I was able to sign into iCloud from A PC to recover my files & will use a PC for future backups if I am unable to fix this problem. What else can I do to fix this problem? Thanks