New Ipad 9 sensitivity is lower at the lower screen

As the title says, I just bought an ipad 9 for the past few days.However, the lower area of screen ( near home button ) is less sensitive to my touch ( slower response, not very slow, just slower compared to upper area ). I can still swipe and write as usual as the delay is not that much ( maybe difference - 0.05s compared to the upper screen ). But I can feel the slight different compared to the upper screen area which is more responsive to my touch. Is this normal or should I replace it with a new one? Or the seller give me an ipad that has experienced screen damage before? Tqia