This started when my brother in law set up my TV as a second screen for my PC. Ever since he did that when I use, for instance, CRT new pixie, (in retroarch or in reshade on stuff like Sega Model 2 emulator) I get these wild blown up rolling scanlines all over the screen. Instead of being in the background and only terribly visible on bright backgrounds, they are everywhere at all times, even on darker colors. If I try to turn them off, they just freeze in place, still exactly as shown in the attached images. Any ideas what could have gone wrong? If I play in windowed mode it's back to normal. But the second I go full screen I'm wearing the glasses from They Live AND I SEE THEM. Any ideas what could have happened to make this sudden change?
This was happening only on my PC, but is now happening on my TV as well.