I think you may be accidentally touching the screen with two fingers.
Completely unavoidable... I've tried holding my phone differently but at some point I end up doing it with the slightest movement of my hand
It's even worse with my phone case off since the Samsung galaxy series has the edgeless screens
I would strongly recommend playing on PC/Mac anyway, it's what the game is designed for.
I don't own a pc
Yup. Happens to me occasionally, too—not because of two fingers, but because I sometimes drip ejuice on my tablet's screen (classy stuff, I know). Not a big deal though, not sure why anyone would complain about this.