About 2 weeks ago (I think when I updated to MacOS Sierra) the keyboard keys quit being lit when I turned it on. F6 will cause it to light up (and F5 to dim), but, it won't stay lit. Covering the light sensor (which should cause the keyboard to light up max) doesn't do anything. If I reboot, or shut down then power back up, the keys are not lit again. Controls are set for automatic, and I'm not sure where else or what else I can go or do. Is this working as designed with Sierra, or, is there something I need to do to fix? Thanks.