Slown in game

[lighttigerXIV]

Hi, i don't know if it's the kernel or a MIUI thing. Normally i play a games wich is PES 2020 and on Pixel Experience it's a smooth experience. I tried using smartpack kernel and it kinda works. But after some time the game starts losing fps and becomes unplayable. I have the same issue on every MIUI Roms. Is there a way to fix this(I really want to stick with MIUI)
Appreciate all answers