Manually setting/adding the TV EDID (Extended Display Identification Data) - might help (or at least - it should do a better job - than automatic detection).
I’m still new to CachyOS, but there’s not much difference - here’s one way to set it: Refresh rate issues after sleep - #4 by Bohjadok (different OP issue - so check just the last part).
Yeah, Wayland has far better support - among the prime advantages over x11 and its primitive bits, but hey - was worth to try. To bad it doesn’t work… out the box - tho, even if you can get it to work - Wayland is still the superior choice. Are you using the proprietary Nvidia driver or Nouveau (tried both, and it’s same)?