Touch works erratically

The touch screen does not work as it should. I can not activate the key correctly, some times something happens but mainly not. After a while the machine will start movements erratically, like it would choice itself to activate the one or the other key; the screen is then showing what happens ! After installation of the new firmware “Snapmaker-GD32Base-2.2-beta” (update.bin), no improvement !
I think the touch ist not working correctly and need replacement.

My Touchscreen is behaving very similiar, though it seems worse while in laser mode.