Help...iPhone constantly asking for password

[luvmymbp]

My iPhone 11 is constantly asking for my apple id password. Updated to 14.7.1 thinking that would solve the problem but it didn't. Have restarted the phone & changed my password with no luck. I've read most of the online suggestions and they're all similar...sign out of icloud, turn off/on imessage & face time, reset phone, etc. Would two factor authentication make a difference? Don't have it enabled yet. Hoping someone on MR can help. Thanks in advance?

 

[now i see it]

This recently happened (last week) to my iPhone 6 Plus running iOS 9.3.5 (ha). In the middle of the night when I picked up the phone to check the time, I was greeted with a "you must change your passcode" alert that could not be bypassed.
So I did change my passcode but it wouldn't let me finish setting it up in iCloud - so I got a warning message for a few days constantly nagging me to finish setting it up - which it wouldn't let me.

Eventually a few days later it did stick and the nightmare ended.
Such a LAME way to do things. Very un professional