Dell G7 7588 broken pixels

I had my motherboard replaced a few weeks ago. Just after the replacement, my display started to misbehave. Sometimes the screen goes black for a few seconds and comes back on out of nowhere even while working on MS Office or just sitting idle (no it's not the sleep timer). I can handle that but then there are broken pixels. I thought it was some sort of driver issue at first. But then I recently did a fresh install of Windows 11 and the problem is still here. Moreover, I have a dual boot and the problem persists in ubuntu too.

I did some weird tests on my own to diagnose. Restarting obviously helps. But if I were to change the wallpaper right now, the ghost pixels would go away. What's interesting is that the other tabs (eg. file explorer or chrome) have no issues. Also, if it were some kind of display issue I don't think I could take screenshots of the thing. I suppose somehow my system is rendering the broken pixels.

Can someone help me?

I can screenshot the weird pixels????Moving cursor over the broken pixel doesn't helpDrawing over broken pixel doesn't help