Cont'd: iCloud for Windows 10 keeps popping up

This was now OK for more than a year and doing its job quietly.

Some days ago, iCloud app started popping up again and again.

Normally, it's always activated. When popping up, I'm logged in. I only need to close.

But it looks like, it's not working properly, because the shared albums are not synchronized since a week.

All recommendations read so far, are "not satisfying":

(log-off / log-in) or even (un-install / install) will result in loading all shared albums (thousands of family photos, GBs of data) again and to another folder. (I had that several times in recent years.)