EDIT: This is now solved thanks to @Amarok! Solution is here. Changing the refresh rate from 60 Hz to 120 Hz fixed it.

My husband and I recently upgraded our TV to a Samsung Q70, and I have started experiencing an odd issue, visible in this video here.

The Issue

There's a horizontal section across the entire bottom of the screen that seems to be refreshing later than the rest of the TV. The game is running on a PC hooked up to the TV via HDMI, and the TV is running on game mode. This issue did not happen on our last TV (a 10-year-old Visio that I don't remember the model number of).

The Oddness

• It doesn't happen on the desktop or in video inputs.

We've been watching YouTube and Hulu through a Shield TV that we also have hooked up, and this issue isn't present in any of those, nor is it visible when I'm using desktop applications on the TV through the PC.

• It only happens in certain games.

The video is from Trackmania 2: Lagoon, where it is always present. Meanwhile, it is not present at all in Trackmania (2020). Likewise, I've been playing 428 Shibuya Scramble where it shows up in the exact same way in the exact same area, but it does not exist in Distance or Rogue Legacy, for example.

• It does not respond to v-sync.

I've tried toggling v-sync on and off, both through the game itself and forcing it through my video card. Neither alleviated the issue. The display looked the same whether or not v-sync was turned on or off.

I'm looking for any guidance anyone can give me, especially if this is a hardware issue with the TV itself, since I'm still in the return window.