Auto-brightness appears to be broken (10.13.2)

Hello

Running High Sierra (10.13.2) on a 2016 MBP, and last night I noticed that the screen didn't dim when using it in the dark. I have just been into the display properties and fiddled with the auto-brightness toggle, and the display brightness slider didn't automatically adjust. The only way I can adjust brightness is manually.

The issue occurs both on battery and power, and affects all accounts.

To clarify, I'm NOT using an external display.

Could someone with the same model MBP (15"/TouchBar/dual graphics), running the same version of HS, check to see if it's an issue for them...? Or are there people running 10.13.2 on a different model who are also having problems...? If it's a bug, the more people who find it the better (although I'm not going to hold my breath waiting for Apple to acknowledge it, never mind patch it!).

So get finding, folks!

SJ