Screen Unresponsive (Unresponsive at Lockscreen most of the time)

Happened some time ago, not sure what causes it.

Was on Jailbroken iOS 8.4.1 and updated to latest version (iOS 9.2.1) but it doesn't solve the problem.

The screen was replaced 6 months (or longer) ago, replaced it by myself through the guide here.

Screen is unresponsive most of the time in the lock screen if I don't unlock it in 20 seconds or more, so I'll have to force restart my phone a few times for it to work again, sometimes applying pressure on the screen where the flex cable from the LCD is connected to the phone (Upper right side).

Screen will be responsive again continuously when I'm playing game or scrolling through Facebook with it unless I locked the screen for more than 15~20 seconds,

There are also some people saying it is iOS 9 problem too... so I'm very confused.

It's really annoying that I have to force restart it almost all the time.

Also I've already accidently lost the Front Panel Assembly Cable Bracket, maybe that is the cause?

Thanks in advance, sorry if my English is bad.