Help Adding Player on my already registered Gran Board 3s

So I have my profile registered and set up. But I want to add my dad so when he comes over to play he doesn’t have to show up as “Guest 1”.

I go to add player, it says to do so on Gran Player app.

I go to that, set up his email and name and gran ID, but then I still can’t find him on my main account to add. What in the heck is happening? Please help!