Virtual buttons lock touch screen input

[Onso37]

Pressing one of the on-screen buttons locks touch screen input, which makes stuff like playing the flute in Spirit Tracks quite cumbersome. I'm on Android.

[i8890321]

I think i facing the same issue, I played the Spirit Tracks with melonDS inside the retroarch (Android phone).
When i press the overlay buttons (L2) for my blowing mic action, my dragging and holding on the screen lose and the flute reset to the middle.