I use dual monitors with my PC. When I want to play PS4, I unplug the HDMI connecting my PC to my main monitor and plug in an HDMI that's connected to my PS4. I've been doing this with a Samsung monitor for years without any issues. Today, after doing nothing different than any other day, the monitor suddenly doesn't detect the PS4 at all. The results are the same no matter what HDMI cable I use, and my PS4 will connect fine to other monitors.
The only clue I have is that before today, when I would unplug the HDMI connected to my PC from my main monitor, my PC would recognize that it's now only connected to one monitor, and switch to a solo monitor display automatically. But now when I unplug the HDMI connected to my PC, my PC still thinks that there's another monitor connected. Even when I unplug the HDMI cable from my PC, it still thinks there's two monitors connected.
I've tried all the obvious stuff. Rebooting everything in every possible way, updating all the drivers, tried every different setting on the monitor, tried manually changing the display to solo monitor then trying the PS4, etc. Nothing will make the monitor detect the PS4, even though this same monitor works fine with my PC, and the PS4 works fine with another monitor. This is the most confusing and honestly creepy tech issue I've ever had, and I haven't found anything helpful anywhere else online. Please assist.