yeah I'm facing the same issue. i also bought this phone for gaming. but i can't play pubg. the touch issue is worst. it stops registering the fire button touch so i have to lift my finger and then touch again to fire normally.
i use 4 finger claw in pubg and sometimes it's soo buggy that if I'm aiming in front then automatically the screen moves to other direction. and to be honest my redmi note 5 pro worked better than this 28k phone. the only problem i faced on note 5 pro was that it lagged soo much and can't play on 60fps. that's why i purchased this k20 pro. but now i think i just wasted my money.
i hope they fix this issue soon so that we can play our games as we wanted. most of the people have bought this phone just for performance and gaming i hope they keep this in mind and fix this.
or i shall sell this and buy a better phone than this crap.
fix this with the next update Xiaomi.