Also i noticed that in always on display there's a weird flashing of screen (a very small spot). Screen isn't defective by any means as the issue wasn't in ob1.QUOTE="neildalal, post: 84460235, member: 5671938"]
That's a known bug that currently exists. Network breaks sometime after installing viper. I don't know if there is any fix available.
It also flashes for half a second before screen turns on. when you press the power button (the time between power button and screen lighting up)
Yes, that's the software implemented proximity sensor doing it's work. You can try covering the top part of the screen and the AOD will turn off thinking your phone is in pocket. Although it is not very reliable and should not be visible so frequently and it should hopefully be fixed in the next update.