Hi willy,
We are still improving auto game mode detection.
In v1.39 for Andoird game mode is disabled when physical mouse cursor is visible. Some games switch from mouse cursor visible (usually in game menu) to non visible during game or after switching to software rendered mouse cursor.
You should be able to switch to game mode at any time using the sliding menu.
Please let us know if you can switch back to game mode manually (after this switch it should stay in game mode all the time).