I had this problem too. I play pubg mobile using scope hold options and I put my scope button on top left of my screen. The issues is when I hold scopes and move joystick to left or right simultaneously suddenly the screen flicker scope in and out, or scope out most of the time while I was holding scope button. This really mess up my with my aim. I not using any tempered glass and already turn off the 3 fingers screenshot option. I turn on glove mode on the issues still happen as well as when I turn off the setting. If you said the problem is from the pubg mobile itself, I tried playing on my xiaomi phones it work pretty well no screen flicker while holding scopes and moving joystick to left or right simultaneously.
