just as in this post: Simultaneous tapping Virtual gamepad example (SOLVED) - #21 by kakerlaka
sometimes the app on the device starts with that bug, that the buttons or stick release although one never took the finger(s) off the screen. then i close the app, kill the task (activity), restart the app and it works. when it happens, it is always the same timespan that passes 'till the button or stick releases. it feels like its around 1 to 1.5 seconds, just like a long tap would feel.