It happens occasionally and I cannot reproduce it manually. The top left (portrait) or bottom left (landscape) part of the screen taps itself sometimes for some unknown reason. I recognize this problem from my older iPhone but that was due to hardware damage and jailbreaks, not sure if restoring my i6+ from the i5 can carry this problem along ? I had the phone for 3 weeks and I realized this a few days ago ... I would have realized it since I got it if the problem existed back then ! Also, the screen sometimes just hangs and stops responding to touch for a few seconds (I usually just lock then unlock the phone) , I noticed this after 8.1.