Did you made a backup of your previous stock rom using TWRP ? IF so revert to stock using Nandroid. Might solve your problem. About your others questions.
1. Screen Rotation not working
2. Knock ON feature not working (screen goes off from double tap but its not turning back on only by power button)
Open dialer menu and type;
5689#980# (Sprint)
3845#801# (T-Mobile)
3845#803# (AT&T Canada)
3845#802# (International)
3845#800# (At&T)
3845#980# (Verizon)
And when hidden menu is showed up, go to "Settings"
and go to "Update Touch Firmware".
The touchscreen won't work until after 5 seconds, Wait for it and if touchscreen gets working, exit the menu.
3. Motion sensor calibration crashing (unfortunately settings has stopped)
Bad flash cause these kinda problem.
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I would be able to help you more if i was getting enough free time. Unfortunately I'm on a hectic schedule these days.
I have twrp backup of stock vs98012b v4.2.2 rom along with all its stuff data, system, cache & efs, restored it many times but it did not solved those issues i had with the phone now the situation is a bit worse i feel like hitting this phone with a sledge hammer
twrp is gone man and my device is now finally soft bricked i have flashed stock based v4.4.2 firmware followed by VS98024A_11.kdz with the help of LG Flash Tool 2014 everything ran fine during installation and the phone rebooted automatically but boot loop occurred the device keep on power on and off by itself now twrp does not exist anymore i only have download mode available...
Also i don't know why the hell i am unable to flash the factory rom of my device VS98012B_00.kdz the installer just finishes in few minutes and say process completed but nothing happens on the phone still booting on old rom that flashed before...
Now what's happening this action is keep on repeating:
LG logo appears after bit loading it reboots into maintenance mode then back to normal mode is there any way to fix this:geek2: