Help screen glitch

[Maxlee1255]

Basically the main problem I keep getting is that the screen will just go black as if I've locked my phone but it will flash back on when I take my finger off the screen, for some reason it will only happen when I touch the screen.
It also seems to happen more if I'm holding the screen horizontally.
I've reset to factory and used the repair tool both do nothing.
I'm guessing it's some setting but I haven't been able to work out which.

 

[Tyseyh]

Not sure if this is it, but look under Developer settings for something like, show flashes.

 

[Maxlee1255]

Nope they were all switched off but I did find a setting that keeps my screen on while charging that will help a lot since I play on my games while the phone is charging in work. xD