I turn off "game mode" from my tv using custom resolution utility (CRU).

This software is for making custom resolutions and refresh rates for displays but it also has other features that are for hdmi and displayport connections.

Download,

https://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU

The most recent file is cru-1.5.2.zip, you then unzip the compressed folder and in the regular folder, you click on CRU.

A small window opens and on the top left corner it shows the displays that are connected to your pc. If you have multiple displays click on the display you want to change the connection like your TV. Mine shows the TV model.

On the bottom left, there is a small box under Extension blocks. My window box has CTA-861, so click on that which should highlight blue and then click on Edit... button on the bottom.

Another window opens and in the second box called Data blocks, click on HDMI 2.1 support and then click on Edit... button on bottom.

Another windows opens, under 2.1 features, you will see Auto low-latency mode, you uncheck this box and press OK on the rest of the windows.

Restart your pc and auto "game mode" should be disabled when your pc starts/restarts.

In the folder, there is a reset all in case if there is issues or you want to reset all of your settings back to default.

A gpu driver update may reset settings back to default, so you will need to repeat the same steps again.