“Turn On Your TV with Your Remote” option doesn't power off TV with new 2021 Siri Remote

I have enabled HDMI-CEC on the television (Telefunken XU65A401 model) and I am able to turn on the TV via the power button on the Siri Remote. Using the power button again does not power off the TV though, the "Press and hold to switch everything off." message implies that this is possible.

In the "Remotes and Devices" settings the HDMI-CEC option sometimes displays as "Control TVs and Receivers" (On) and sometimes "Turn On Your TV with Your Remote" (Off). Attempting to enable the “Turn On Your TV with Your Remote” option results in a "You can't use System Control with this configuration" error. Powering on the TV works no matter what option is displayed.

The first time Settings is opened you can actually briefly see two options displayed:

Apple TV A1842 (64 GB)

tvOS 14.6 (18L569)