If your screen is acting up (random behaviours - random swiping or random characters etc) and as it's happening on 2 screens, you either have 2 bad screens or:
1. The touch connector ribbon is not connected to the motherboard correctly
2. The touch connector (FPC) on the motherboard might be damaged - remove the screen and inspect it under a good light source
If you obtained the 2 screens from the same place hopefully that's where the problem is and not with the motherboard. I've seen a few third party screens coming out of China that have weak touch connectors. They don't snap / click into the motherboard like they should. The main LCD connectors are fine.