LG makes some of the best gaming TVs, especially the bright and vivid CX OLED series, which not only supports 4K at 120Hz, but also G-Sync and FreeSync. So Nvidia's new GeForce RTX 3000 series should be a perfect match on paper, as both devices support HDMI 2.1 and all its clever tricks. In practice, however, some nasty bugs have cropped up.

One of the problems affecting LG's OLED TVs when paired with a graphics card that supports HDMI 2.1 is getting G-Sync to work correctly, or at all. This also affects other TV models.

"On my B9, I can confirm that G-Sync either does not display at all, or if it can be displayed, turning it on causes the screen to glitch out, artifacts, huge vertical blocks of the screen to go black, signal breaks, and finally no signal at all! You can see it," one user stated in a Reddit thread on the topic.

In PC mode, there is also a problem with a type of compression called chroma subsampling. The affected models are supposed to support operating at 120Hz 4K resolution in RGB 4:4:4. However, LG's high-end TVs instead display 4:2:2 at 120Hz, which compresses the image and in some cases can result in significantly poorer picture quality.

This is not something one wants to see after investing a lot of money in new hardware. However, LG deserves credit for being transparent about the problems and working quickly to correct them.

"LG is aware that some LG OLED TVs have compatibility issues with the recently released Nvidia RTX 30 series graphics cards. Updated firmware is in development with plans to roll out to LG's 2020 and 2019 HDMI 2.1 compatible TVs within the next few weeks, which should address these incompatibility issues," LG said in a statement.

LG is making good on its promise: Vince Teoh, a TV reviewer for YouTube's HDTVTest, obtained a beta build of the upcoming firmware and confirmed that the G-Sync incompatibility and chroma subsampling issues he had also observed were indeed fixed He confirmed that the G-Sync incompatibility and chroma subsampling issues he had also observed had indeed been fixed.

Teoh tested the updated firmware on a GeForce RTX 3090 loaned to him by Nvidia. The only minor issue he noticed was that the menu incorrectly indicated that the signal was an SDR signal, even though it was an HDR signal. However, this did not seem to affect the output, and may be corrected once the beta firmware becomes final.

Speaking of which, the final version of the firmware should be arriving soon. In the meantime, owners of C9 models (2019 OLED TVs) in Europe and the US can request the firmware from their local LG service center, Teoh said; owners of CX models (2020 OLED TVs) can receive it via wireless update in the coming days .