AppleTV only allows 2 Users to select from on main screen

I have just setup my 2 kids’ Zwift accounts and they will be using the same Apple TV 4k as I use however on the initial loading screen I can only have 2 users logged in to select from, if I log both of my kids in it kicks me out and I have to enter my username/password again to use Zwift? The passwords I have used are pretty secure so it is a massive pain to have to enter these every time one of us wants to use Zwift. Why is it limited to remembering 2 users?

If it wasn’t annoying, it wouldn’t be Zwift!