Strix g731gw, black horizontal lines at the bottom of the screen

[plzletmein101]

Case ID: E21010159035
Hello and thank you for helping me.
I have black horizontal lines at the bottom of the screen. The first time they appeared was after closing a certain game.
They DO NOT appear in screenshots.
They DO appear in safe mode.
They DO appear in bios menu.
They DO appear in clean boot.
They DO NOT appear in other displays using hdmi
However, this will get complicated a bit: Changing the refresh rate from 240hz to 60hz then back to 240hz clears the lines for the 240hz, but only if the 60hz had the lines. However it is not a true solution, because turning off the screen or putting the laptop to sleep, brings the lines back.
Turning off the screen at 60hz removes the lines if they exist, or bring them back if they don't (kind of like a switch).
The only weird solution I found is to switch from 240hz to 60hz, then turn off the screen if the lines aren't there, then once I have the lines back, switch back to 240hz, and that will clear them. I don't think it is hardware related due to this weird temporary fix.
I did try a graphics driver clean install using "Display Driver Uninstaller", it didn't help.

(everything bios, windows, apps, drivers are up to date)
OS: Windows 10 64bit
Bios: G731GW.308

I am posting this here because the Asus support team replied that it is a hardware problem but seeing that it can be fixed (although temporarily) through turning off the screen and switching refresh rate, I think it is more of a software issue related to the display or refresh rate controller.

Edit: Update: The previous solution works rarely now, however turning off the laptop while using 240hz and then turning it on again, clears the lines (must be a shut down then start up, cuz reboot didn't solve it)
Video upload:

[plzletmein101]

After asking them to reread my email again because it doesn't appear to be hardware related. They just replied yeah it is a bug, and do a factory reset....
Please any help would be very welcomed

[Blake@ROG]

Hello plzletmein101,
Please PM me your SN.
And may I have a video of the whole issue process? from you have line til you don't or the other way..
Thank you so much.

[plzletmein101]

Update: The previous solution works rarely now, however turning off the laptop while using 240hz and then turning it on again, clears the lines (must be a shut down then start up, cuz reboot didn't solve it)

Hello plzletmein101,
Please PM me your SN.
And may I have a video of the whole issue process? from you have line til you don't or the other way..
Thank you so much.

I will send you the SN

[Blake@ROG]

Hello plzletmein101,
Thank you so much for the SN.
After consulting, please kindly send the device to our service center to check for the panel and cable.

[plzletmein101]

Hey Blake, thank you for your reply
I currently live in Tunisia, can you tell me which service center can I go to?