Touchscreen Issue (after upgrading to 5.1.1)

Brightness slider wasn't responding to my touch sometimes, so I checked out the touch screen service test via *#*#7378423#*#*. Sure enough, major no-touch spots particularly with horizontal movement on the space near the top of the screen. This problem only began since the update to 5.1. Thoughts? Besides rolling back...worried it's a hardware issue?

Have a screenshot of the service test but unable to post here. If needed, let me know.