Interesting development... I am back in the US and used my (very old) ipad as a trusted device to finally get rid of the pop ups.
To no avail.
I changed my password.
Everything works but the popups remain.
And all my pictures (fortunately I only had shared pictures there) have disappeared.
Thank you apple for all the frustration.
I am at this point seriously considering getting rid of everything apple (email addresses, icloud, a lot of puchased music, movies, tv shows, etc...)
The only reason I am really holding on to apple stuff is the ability to get shared pictures from my niece (who has no idea how to share them in any other way) and a shared calendar with my daughter...
Unfortunately my family is totally apple minded since I introduced them many many years ago to ipod, ipad, iphone and all the wonderful things apple realized back in the day.