Back button/Recent Apps backlight flickering and lagging phone. (Galaxy S6)

[Android Central Question]

Hey all,
I recently got given a galaxy s6 which had a lag problem. I figured out that every time it lags the backlight would light up. I think this is caused by a bubble under the touchscreen when it was dropped by the previous owner. There's two other posts that have the same issues but neither solved my problem. The most optimal fix would be to disable the broken buttons and just use software keys.

Things I have tried:
-Wiping Cache
-Safe Mode
-Disabling the back light using an app
-Using root explorer to edit generic.kl ( this worked for a little bit and then at the end of the day it went back to normal)

2 other posts:
https://forums.androidcentral.com/ask-question/731192-my-recent-apps-back-buttons-my-s6-keep-flashing-why-doing-how-do-i-stop.html
https://forums.androidcentral.com/ask-question/814307-why-my-recent-tabs-back-key-flashing-nonstop-whenever-using-galaxy-s6-edge.html#post5874923

Any help would be much appreciated. Thanks

 

[Alf Stewart]

I also tried just factory reseting the phone still nothing. Is there anyway to physically disable the backlight by disconneting a cable or something. Im op btw, just signed in.