Predator X34P with a line right in the middle of the screen

[HumdrumPenguin]

I bought a Predator x34P on Amazon about a 3 weeks ago, and I could see a faint line right in the middle on the screen only on a grey background. Both sides would have the same colors though. Since yesterday the line has been very easy to spot, no matter what background I had, and the colors on both right and left sides are clearly different now. I brought back the overclock from 120hz to 100hz, updated the displayport firmware from Nvidia, turned the monitor on and off several times, clean installed latest graphics card (gtx 1080) drivers, tried different resolutions and refresh rates, and although I could have it back to just a faint line on a grey background twice, the line got aggressive again not so long after. Is there anything I'm missing here, or do I need to send back to Amazon? I really didn't want to send it back, because monitors nowadays are a pain due to poor quality control, and that goes for all brands. I've got no backlight bleeding, no dead pixels, and low IPS glow. I really want to solve this line problem and keep the monitor if possible. PS.: the picture bellow shows 2 lines, but that's just from my camera. To the naked eye, there is only one clear line, right in the middle.

 

 

[HumdrumPenguin]

I was just tinkering and managed to put it to its former state. The line now is only visible on a grey background, but right now the monitor is at 100hz, not 120hz like before. Changes of the line getting worse again are pretty high btw.

 

 

[HumdrumPenguin]

Also tried the HDMI connection, and checked it in the bios. It was still present in the bios, rendering all other tests useless. The panel is defected and needs to go.