Hi Biff,
Thanks for the question! Our KD55X80K does not support all the features associated with HDMI 2.1. This TV supports HDMI eARC/ARC, Auto Low Latency Mode and has a panel refresh rate of 60Hz. Make sure your device is connected to the HDMI 3 or HDMI 4 input on the TV using a Premium High Speed HDMI cable.
Note: For expanded HDMI 2.1 feature support including 4K at 120Hz signal format, VRR, and ALLM , these features are available on our 85" X80K, X85K, X90L, X93L, X95L, A90K, A80L, and A95L.
Should you need further assistance, feel free to contact us by sending an email to to Sony E-support that you can find on Sony’s official website. Unfortunately, due to the current Best Buy phishing protocol for your protection, we cannot provide a direct email or phone number for customer support as of now. Please find Sony Electronics' Support information: Go to our support website > click on “Support” > scroll down click on “Contact Support” > click on "(TV & Projectors)" and from there you'll see different ways to contact us.
Additional information:
Enjoy an intuitive smart TV experience with natural color and clear sound with the BRAVIA X80K LED TV. The powerful 4K HDR Processor X1 reduces digital noise and boosts details for lifelike picture quality. Google TV gives you access to all your favorite streaming apps, while Google Assistant easily searches for content and controls your smart home simply by using your voice.
Hope this information helps! - Kris