Why do settings mysteriously reset on the iphone11? And iPad? and Macmini?


I'm putting this under "iPhone" since it usually seems to be where the most issues come from. I'll have my iCloud photo set, my info on the contacts, sharing all set, etc. Then for some reason, for example, this morning, my photo in iMessages has vanished. It's on the iPad, but not the MacMini or the iPhone. I hook up the iPhone to sync manually (last sync was three days ago apparently).

Why does this happen? Then, this morning, checking contacts I see that now I'm suddenly sharing my birthdate in the contact. No. I had that unchecked. Now it's mysteriously checked. The address has vanished from the card. It was there two weeks ago.

Invariably, I can get the iPad and iPhone showing the same iCloud info, but my photo will be gone on the MacMini. Only way to get it back is to hook up the iPhone or iPad to it.

This morning, I had 100+ mail messages. I read or deleted half of them. The badges on the Mac, iPhone and iPad do not match. However, they have in the past.
Currently I have 12 messages on the phone, 32 messages on the iPad and 23 on the Mac mini. And all three are on the same wifi network, the same iCloud, supposedly.

Why does this happen?