When I have trouble connecting to iCloud, I always check here to ensure everything is set up as I think it is.
Manage Apple Id: https://appleid.apple.com/
When I have trouble connecting to iCloud, I always check here to ensure everything is set up as I think it is.
Manage Apple Id: https://appleid.apple.com/
Do you have access to another network where you can try to log in?
Try a restart.
Try a forced restart.
unable to connect to icloud when upgrading plan