Had to activate the overlay permission manually at first, then the game and the mod worked for the first time I played... Until the next time I opened the game.

On the next load the coins went into negative 9K or something. I played around with the toggle, gained more coins, nothing.

Cleared cache. The game restarted the progress but the mod did nothing at all.
Reinstalled, rebooted the device - still nothing. Super weird!