Poco X2 Have Powerful Snapdragon 730 Processor but it's not Flagship level, 730 processor based on mid range budget segment processor.
But poco x2 have give option to change display refresh rate 60Hz to 120Hz
That same Time pubg gaming performance is very hard to maintain the peek performance
Poco x2 play pubg on HD Graphics and 30fps maximum, and you change graphics level smooth then choose fps on 40.
Then Mobil has been reached 45degree on 1hour gameing, so please set display refresh Rate to 60hz and Play pubg .