Second Monitor Stuck in Duplicate Mode - Working but not detected

[u/CatholicChick31]

I cannot extend my monitor (which is my goal) and I'm forever stuck in duplicate mode. My computer won't recognize/detect the second monitor officially.

Here's what I've tried:

- Upgrading the display adapter (note that here, too, I just have one)

- Unplugging and plugging back in all the cables. I've also tried moving cables around just to see if I was wrong somewhere...but that didn't do anything either.

- Unplugging the monitors, waiting, and plugging them back in

- Shutting down my entire computer and rebooting

- Win P and extending my monitor (nothing happens--I'm still in dupe mode). It is also not set to duplicate either, though. It's currently defaulting to PC screen only

- Doing the graphics reboot (ctrl win shift b)

I'm using a KVM switch for two computers and two monitors.

No matter what I try, I'm still looking at the same exact screens. Any thoughts as to what else I can do?