Endless iCloud login loop on Windows 11

I have been using iCloud on my Windows 11 laptop for 6 months with no issues at all. Suddenly yesterday after a system reboot I was prompted for my login details. I entered my iCloud id and password. Prompt duly appeared on my iPhone, I click 'Allow' and enter the security code on my PC. The Apple wait spinning circles appears for a while, then the iCloud window vanishes. So I then start the program again manually and I am right back where I started, with the request to log in. It's driving me nuts now.

I've read that users uninstalled the app and it helped. If I do so will I lose all the photos that are currently part of my iCloud? I'm hesitating to uninstall for fear of losing them. Thanks,