Not able to login to iCloud on Mojave

Hello,

I know my OS is outdated, but before I update to anything newer (and lose access to some of the old apps I need) I'd like to see if there's an easy solution.

My iCloud login window (from settings) is hanging after I input email address. Alternatively (from the same window) when I press "Forgot Apple ID or Password" - nothing happens.

I'm able to login into icloud.com in Safari, but Drive and Notes are showing "There was a problem loading this content." While if I login with Chrome I'm able to see all the contents on the icloud.com

I tried quite a few things about a month ago (like install Mojave (on top, not clean install), turn off SIP and looked at some plist files because I thought some issues with keychain, looking at console for errors (and googling them), logging in safe mode has the same issue still), but already forgot the exact details of many so if you have ideas what I can check - I'm happy to try.

thanks