Chosen Solution
Hello. I have replaced the back glass for my iPhone xs Max and after the replacement I have two yellow marks on the screen, top right corner next to battery and bottom left. I replaced in the same day the back cover for an iPhone X flawless and now my xs max has this. Will attach pictures Thanks for the answers. Can I fix it witouth replacing the screen, or it will get worse ?
Cristian that looks like pressure damage (can’t totally exclude heat damage but I am certain you were careful with your heat gun). Give it a couple of days and see if it straightens itself out. Ultimately, I would be looking at a display replacement.