Solar Sensor: "Use device sensor if available" option has no effect

[Thysbelon]

All of the number choices (0-10) for the core option "Input & Auxiliary Devices>Solar Sensor Level" work perfectly.

However, there is an eleventh option for the solar sensor level that isn't documented and doesn't seem to function. It is the option "Use device sensor if available".
I assume this option is supposed to use the host machine's ambient light sensor to set the level of the emulated GBA solar sensor; but on both my Dell XPS 15 9530 laptop, and my Pixel 3a phone, the emulated solar sensor level was always at zero when "Use device sensor if available" was selected, even when I shined a flashlight into the laptop's and phone's ambient light sensor.