iPhone 12 Pro Max Touch sample rate lag/stuttering?

So I bought an iPhone 12 Pro Max from the apple website just received it a few days ago but I quickly noticed something weird, so when I’m scrolling it’s perfectly smooth because it’s sampling at 120hz but for some reason it feels as if the sample rate drops frequently for no reason and ends up looking like you’re dropping FPS in even though clearly it’s not actually the frame rate of the software I tested and confirmed it with cod mobile I ran a simple test where I get my finger and swipe from side to side and it will start smooth and get rough and get smooth again in random intervals, did similar motion with a controller using a Joystick and not stuttering affect what so ever the game was super smooth the whole time, my guess it’s a bug with software, or even worse a defect? I’m not sure but it’s like it has a hard time trying to track ur finger’s position and ends up stuttering.

weird….