Make sure your HDMI 2.1 compatible TV has the latest firmware updates (see below). Activate HDMI 2.1 support, HDMI 2.1 Variable Refresh Rate support, or G-SYNC Compatible support in your TV’s settings menus (each manufacturers’ settings and options differ, so please refer to the manufacturer’s manual and/or website for steps).
Using the HDMI cable, connect your display or gaming monitor to your GPU. Open up the display’s internal settings, look for variable refresh rate, and enable HDMI 2.1. Then, right-click on the PC and select “Nvidia Control Panel.”. Choose display and then “Set Up G-Sync.”. Select “Enable” and click on “Apply.”.I read an article earlier which made this point: "If you're buying the more budget-minded Xbox Series S, the console also has an HDMI 2.1 port, but it instead targets a resolution of 1440p at 120fps, which HDMI 2.0 can already support. But using 2.1 on the Series S will still give you the benefits of dynamic HDR as well as improved color and Monitors with HDR and Freesync that only have display port 1.2 and HDMI 2.0. Troubleshooting. Many gaming monitors ship with refresh rates faster than 144hz with Freesync and VESA DisplayHDR 400 support. Sounds great, but it is common practice for these displays to only have an HDMI 2.0 and DP 1.2 for input. For Example - Acer Nitro VG271 Pbmiipx.
This HDMI fragmentation is also why some of the latest HDMI 2.1 TVs don’t support VRR: it is not a given just because you have an HDMI 2.1 socket. It will be less of a headache by the end of
PaucP.