replacement touch screen not working BUT only for specific cases
So I purchased a replacement screen from ifixit for my iPhone 8+ a few days ago. Installation went without a hitch that I know of (it is my first time doing this kind of repair) and everything seems fine (camera works, screen works, etc.) there is a tiny spot on the screen that is slightly brighter than the rest (backlight?) but the touch functionality suddenly stopped working. I figured out that this only happens when I use Apply Pay and I need to hard restart the phone every time I use the NFC. I have since updated the OS to 15.6 and this did not solve the issue. Also, since I've been using the phone for a few days the front camera does glitch a bit (purple flashes) but only for like, the first 10 to 15 seconds then it is stable. Given these two issues (the Apply Pay/NFC one is annoying), what could have caused this and is it enough (assuming it is not because I screwed up the installation) to warrant a request for another replacement screen? Full disclosure but I also replaced the battery at the same time (3rd party; I wanted a battery with a higher capacity so I got one with good reviews). Thank you very much!