Post Repair Display Issues

I've recently been swapping a few screens for friends with busted iPhone displays.

No issues until just the other day when one friend, whose screen I replaced a few weeks ago, reported that the display was giving her intermittant problems.

Check the images below. She says while calling and texting it's fine, however when she's in Instagram she's getting that limited color issue and occasionally the lock screen displays those lines as shown. Again, both issues seem to be intermittent.

I realize this is a shot in the dark but I'm curious if someone else has stumbled across similar behavior. I'm hoping it's just a loose wire or maybe a grounding issue and not a defective screen but... I'm not optimistic.