I noticed a few weeks ago that some parts of my phone looked paler than they should, and upon closer inspection discovered this "shadow." It starts about 2.5 inches below the top of the screen, and ends about 1 inch above the bottom. The left part of the shadow gets about .9 inches from the left edge, and the right part gets about .6 inches from the right edge. It's not centered on anything, and it's not a perfect oval by a long shot. It's not a display issue, there's either something on the glass or something between the display and the glass. Swiping my finger over the shadow returns the screen mostly to normal for a bit, but eventually it always goes back to the same shadow. The only cause I can think of is that maybe when I bring it into the shower with me, the steam somehow gets into it even though it isn't touching the water (nor even particularly near the water). However, I did the same thing with my previous phone - an iPhone SE 2020, which has worse water resistance than the S24 Plus - and it never had an issue like this.
