New Touch Screen Losing function Over Time

I have replaced a screen on my iPhone 7 plus two times now with the same issue. I purchased the screens from ifixit, and after installation it would work fine... for a short amount of time... then it would start to lose function in random areas of the screen. If I did a hard reset it would come back in that area but be lost in another.

I RMA'd the first one but now the second one is doing it as well.

I have a basic plastic case on it and no screen protector.

Any ideas?