Red Pixels not working on exactly left half of monitor

[matzam]

I replaced the panel on a broken Dell S2716DG and when I turned it on red pixels on the left half the monitor weren't working properly causing narrowly spaced vertical lines to appear and the brightness in the top left corner to be so low it looked like I was seeing that specific area at an off angle.

The pixels aren't stuck but they're much more noticeable in certain circumstances. I couldn't see any vertical lines when the screen was running at 60hz but as I increase the refresh rate they become visible. Certain colours make them more noticeable like the white on the forum make them stand out but not the grey background. Other colours that show the issue are the grey of discord dark mode makes lines appear as do smokes in Counter Strike.
I tried another panel, changing the display port cable, and reseating the internal connectors. I'm guessing one of the internal connectors may be damaged so I found the datasheet for the panel but I'm not really sure what to do now and I'm not sure what I'm reading on the datasheet.

My hardware:
ASRock Z97 Extreme3 - Bios 2.10 (latest)
ASUS PH-GTX1660S - Stock

i7-4790k - Stock
4x8GB Crucial DDR3-1600 9-9-9-24
Samsung SSD 860 EVO 500GB (boot drive)
Samsung SSD 850 EVO 250GB
EVGA SuperNOVA 750 G2 80PLUS Gold

related screen components:
Display port 1.4 cable
Panel - M270DTN01.5
dummy/test panel M270DTN01.3

Any help would be greatly appreciated