how to remove an underage guest account for good

[KaydenChira]

I have installed the game on a device where both me and my son are playing. I set the age to his age (5 yo) and now the game is not syncable between devices. I want to remove the existing game so that I can install or enable a regular, non-guest game account. But every time I uninstall (including clearing the data/cache) the old guest account comes back.

Screenshot shows how options under settings are missing from the guest account (like sign off google)---same on 3 different devices.

Any input is appreciated.

Thanks!

Screenshot_20181118-131927.png