Can't log in on launcher or in game even though my details are correct

Cheesetalker​  As a test, please create a new admin Windows account and try signing into the launcher or game there.  Make it local, as in, not linked to your Microsoft account or any email address.  If whatever is blocking your sign-in is limited to your main account, this will get around it.

Your saves and other content won't be available in the new account, but that's fine for the purposes of this test and can be addressed later if you want.