Question Monitor showing lines at bottom of screen when I start windows

Agent Dash

Apr 3, 2015
I have a gaming PC which is a bit outdated but can still run every new game on ultra graphics settings. It has a 1080ti, 128 GB Corsair Dominator Platinum ram, and an i7 6850k Intel CPU.

I run 2 monitors with it. One is a 32 inch curved 1080p 60 hz Samsung monitor and the other is an AOC 32 inch curved 1440p 144 hz monitor. The AOC is my primary.

When I start my PC and Windows boots up it shows horizontal lines all over the bottom of the screen sometimes an inch tall. It's usually black lines that flicker. Sometimes they slowly go away on their own but most of the time although some go away, there's a bunch left blocking my view of the Taskbar. The lines only show up on the AOC monitor.

When I just use that monitor it still shows them but if I unplug it and use just the Samsung monitor it doesn't show lines on the Samsung. I tried switching out ports on both the monitor and the GPU and I tried using different cables. Nothing worked. Then I tried using the AOC with my PS4 and Nintendo Switch. There's no lines. All graphics card and other drivers are up to date. Just did an in place upgrade of Windows and that didn't fix anything either.

If it's a GPU problem I feel like it would affect my Samsung monitor as well but it doesn't. When I hit the Windows button plus P and choose duplicate, no lines appear on either monitor but as soon as I go back to the extend option it shows lines on the AOC again. This just randomly started happening one day and never stopped ever since. Sometimes turning off the AOC monitor fixes it but not usually. I ran stress tests and mem test. Everything seems to be okay. Ran malware removal software and nothing came up.

I don't understand why it's only happening to the one monitor but only when Windows starts after the boot screen. Any ideas what could be causing this and how I can fix the issue?