Update Apple ID Settings not working

For all three of my Apple devices (MacBook Pro, iPhone 11, iPad Air), when I click on Update Apple ID Settings, it logs in and then out, This is preventing both Keychain and Messages in the iCloud from being enabled.

I've done the usual - signed out/rebooted and signed in. Along with changing the password, and even doing a clean install on each. Nothing seems to work.

I've contacted Apple and it's been escalated to some of their senior techs as it appears to be a an account issue on their servers.

Anyone run into this and have a fix?