60 fps(Extreme) setting now available for Pubg on A15/A16 after recent update(Pubg app update).It is advised to play in cool environment and on wifi connection for longer sessions.
Try Disabling accidental touch protection in settings. I have done same on my A15.Agr pocket sy nikalty waqt ye masla hota ha. Wesy nhi hota phir set hojaega
6 years old phone. So battery surely have degraded. Other than that old models have lesser battery capacity and less effecient chip resulting in shorter better timings.
