Screen tearing help

I bought a gaming laptop for the first Asus tuf f15 12700h and rtx3060m 300hz

I tried tomb raider goty as my first game and noticed constant tearing in lower quater of my screen Also found screen tearing on display while opening reddit website for a couple seconds then it stopped

Then I disabled iris xe graphics using mux switch , now the tearing has been resolved

What's the problem here my excessive 300hz display or my igpu

Please help me out guys I am trying gaming for the first time