Horizontal lines on top left of display. LG 49UH668V

So my screen developed a flicker around a week ago, however this problem was solved seemingly by removing all cables from the motherboard and plugging them back in, I think (I also pressed the heatsink down onto the main IC) I’ll link the related thread below, also if a moderator feels this question should be in the other thread delete this thread and I’ll make a subsection in the other thread regarding this issue.

I’ve noticed that after the flicker resolved there are horizontal lines in the top left hand side of my display and these appeared at the exact same time as the now solved/gone flicker issue, I know this because they aren’t in photos I took of my screen (to remember something in a game, it’s quicker than writing stuff down) where there are no horizontal lines. The lines are very fine (only slightly visible with my glasses on at 6 feet and very visible under 3 feet. I’ll include pictures below. If you see an moiré patterns that’s just a result of photographing a screen with a digital camera, try zooming in and look for perfectly straight horizontal lines.

From everything I’ve read horizontal lines seem to point to an issue with the display itself or the display driver board (in this case boards, there are two) however the fact that it showed up with a flicker that is now resolved has me wondering if there could be any other cause of this problem as both showed up at the same time. Or am I just a very unlucky person and have had two seemingly separate faults at the same time?

Images of the lines on screen:

Close up images of the display driver boards:

Thread discussing the flicker issue:

My LG TV has a weird flicker/strobing/pulsing issue. LG 49UH668V

Thanks in advance.

-David