Replying to
@parisba@cloudisland.nz Find My is probably the reason you can't logout from your devices. Ironically you can even enable Find My while your account is locked (I did at some point, it's just a switch), but then you can't disable it (because for turning the switch off it requires your password, thus a login, and you're locked out of that). Fortunately in my case it was a simple lock due to probably too many invalid password errors and I was able to unlock it by email, but it's a terrible trap nonetheless.