Light Above Volume/Tune Knobs?

I'm starting to think I've lost my mind, but I'm hoping there's some obvious setting I've somehow missed. Ever since I got my 2019 XLE over three years ago, I've found it annoying that the volume and tune knobs were completely unlit, making them nearly impossible to see in the dark. Then suddenly, after dealership maintenance last year, there were two small rectangles of blue light at the top of both! I was surprised and pleased, and went about my life. But then, without noticing what I did, they were gone again.

So did I change something really obvious that my spouse and I are both too oblivious to find despite our combined efforts? Please help me to feel stupid, yet able to see basic controls in the dark.

 

Apologies for disappearing - shortly after I posted, my car was encased in a couple inches of ice. But I figured it out:

When the dash light dimmer is set to full brightness, as mine usually is, it disables the knob lights. It needs to be at least one click below full brightness. Once in that setting, they'll then turn on only when it's dark out. I'm not sure how that makes any logical sense, and it seems to be only those tiny knob lights that work that way, but there it is!

 

Clear as mud and doesn't reference the lights I'm asking about (which are the only ones that behave differently that the rest), but thanks anyway!