Display of iPhone 8 plus has gray stain

Hi there, so this is kind of a long story. I was replacing the ear speaker on my iphone 8 plus and there was a lot of dirt in the grills so i cleaned it with this liquid especially for the cleaning of electronics and unfortunately some of the liquid got trapped between the display. It was a lighter stain that you could see mostly on a white surface from a 40 degree angle. I then used a hairdryer to dry the liquid out and after that it went back a little bit but I noticed a gray stain, which was much more visible that the white stains. Is that just a coincidence or did I damage the display with the heat? Honestly the latter seems unlikely as it's only a small spot, not the whole side of the device I heated. But I googled and didn't find a cause. There are two photos attached, one from the top and one from a 40 degree angle where you can still see the white residue of the liquid. Also, at an angle the gray spot turns bright as you can see.

Thank you so much in advance :)

Best regards,

Adam