Replacement Screen Not Working Properly When Placed Into The Phone

I dropped my phone and cracked the screen and the touch screen started going crazy, always swiping down and pressing random areas of the screen making it impossible to navigate, so I installed a replacement and all is well until I get ready to put it back in the phone. The screen works perfectly fine when it’s outside the chassis, but when I align it up before gluing it back in, the touch screen starts going crazy again, just as it did before the replacement. I’m at a loss for what could be the cause but I suspect it’s something behind the screen?