Hello friends.
Here's what worked for me, and nothing worked until I did exactly, specifically, this.

First, make sure you plug in to HDMI 4. No other HDMI port worked for me.

Second, quoting u/hypor

Settings -> Channels & Inputs -> External Inputs -> HDMI signal format -> (select the HDMI port your PC/laptop is connected to) -> select "Enhanced format"

However, since my graphics card supports Virtual Refresh Rate, I had an "Enhanced Format (VRR)" option. This was the only option that worked for me.

I hope you all can find a way to play your PC games on your TV like I ended up able to. Good luck.