GL504GM Monitor problem with 144hz and fn + f6

[calchung]

Bought this PC for 2 weeks and I am having problems with the monitor in 144hz mode, it has flickering lines across the screen sometimes. Updated both nvidia driver and intel 630 driver still didnt work.

Also, when I pressed the fn + f6, the monitor goes off, and it wont turn back on when I press fn + f6 again.

Any advice or solution?

EDIT: The fn key is fixed after reinstalling the ATK driver.