Blue shadow in setting when scrolling

Hi everyone. I got my Iphone XS last year in may and i used a case for a little while but then i threw it and i actually dis pretty good without case, almost never dropped it. Maybe 1-2 times lightly. However, about 15 mins ago i got tangled to my charging wire and it fell on to the marble floor from about 3 feet and nothing is cracked or broken on the visible side, but, interestingly i just noticed the icons, especially app group icons on the screen seemed little bit awkward when i moved the screen. When i got into the settings, i scrolled down and noticed a blueish shadowish thing that appears as i scroll up and down. So maybe it was there and i never noticed and seemed odd after i dropped the phone and i was just looking for something broken. I took a screen video but i cannot upload it here and can’t even take a screenshot because it wont pick the frame when it happens.Anyone has any idea ?