Apple TV 4K Connection Issue with LG OLED TV

I have two Apple TV 4Ks (one purchased in May 2019 and one purchased last month) and an LG OLED TV (OLED55B6P), which I've had since early 2017. My Apple TV 4K has been plugged in continuously since May 2019 with no issues at all. I moved one month ago, but used all of the same hardware in my new apartment and its continued working perfectly, including streaming a show this morning. All of a sudden this afternoon, I tried to turn on the Apple TV and it didn't work properly. As usual, I turned on the Apple TV by pressing the menu button on the remote, and as usual the TV changed to the HDMI input for the Apple TV. But instead of just connecting and showing me the Apple TV home screen, like it always has, it looked like I was getting static, as if the HDMI cable was plugged in wrong, and after a few moments the TV showed "No Input." I tried multiple times, and a couple times I got some sort of error message on the Apple TV having to do with HDR, but I was only able to see it momentarily before the static-type image took over and the connection was lost.

I tried the Apple TV on a different TV and it works fine. I tried changing out the HDMI cable, but had the same result, and plugged the HDMI cable into all 4 of the HDMI inputs on the TV with the same result. I swapped out the power cord - same issue. I tried all of these combinations with both of my Apple TV 4Ks and had the same result. All the while, my Cable works completely fine on the LG OLED TV. And both Apple TVs work perfectly with my other TV (some crappy old non-smart LG). So I am at a loss, it seems the LG OLED TV just stopped being compatible with Apple TV 4K, which doesn't make any sense to me.

Any advice would be greatly appreciated!