Thanks Eric, for your suggestions. Things have finally begun to resolve and fall into place. It's been since July that I've had Apple ID settings error messages. Getting rid of Tunnelblick helped but that wasn't the source.
None of the other ideas here (not just from you--from anyone) have worked.
Hours on chat and on the phone with Apple support did nothing ( although I did later use the unplugging and hard reset they taught me).
It took trial and error with settings. Not only Apple ID, but iCloud, and especially iCloud setup.
Changing from protonmail to iCloud mail didn't do it, and I spent many hours making that conversion.
On the whole, I'd say this experience has been worse than anything I ever encountered in 35 years of using PC compatible & windows machines. Apple is great out of the box, but God help you if anything ever gets screwed up. Their support hasn't been worth spit for me. I paid a lot of money for Apple Care+ and have gotten nothing. I got as far as calling my nearest Apple store (over 100 miles away) to request an appointment. I followed their instructions for doing that and they ignored it. While I was waiting on them, I happened across the solution on my own.
On an unrelated matter, I contacted Xfinity (Comcast) my internet provider, to ask about changing the email address they assigned me, which was 17 digits (useless!). While waiting on hold I came across the solution on about my fourth try. They came back on and told me it was impossible. I did it, so I guess I can do the impossible! All this is to say that tech support in many places has gone totally to ****. If they tell you wrong, to me, that is worse than worthless, it's dangerous.