MX Keys S keyboard brightness keys don’t work after pairing (Bolt + Bluetooth)
Environment:
- Mac mini, macOS 26.3
- Logitech MX Keys S
- BetterTouchTool 6.193 (SetApp)
Issue:
Keyboard brightness up/down keys do nothing after successful pairing. Reproducible on both Logitech Bolt receiver and Bluetooth. Battery is full.
Steps to reproduce:
- Pair MX Keys S (Bolt or Bluetooth)
- Press keyboard brightness +/- keys
Expected:
Keyboard brightness turns on / adjusts.
Actual:
All LEDs light during pairing mode, but turn off immediately after pairing and cannot be turned back on via keyboard brightness keys.
do you have the Logitech Configuration in BTT set to make all special keys available to BTT? in that case the default functions for the keys will be gone and you need to configure them in BTT
Yes, I have re-paired via Bluetooth, reset the logi config and selected MX keys S, ensured check all keys remap, applied settings. I also changed the shortcut several times to increase keyboard brightness ⇧ +⌥ + Up (not using Fn or F4) but it still doesn't work.
if you want tghe keys to maintain their standard behavior you need to UNcheck the"make all keys available dor remapping in BTT"
Alternatively you can record them in the BTT keyboard shortcut section and assign the logitech brightness change actions
You know what, it suddenly started working again after I turned it off, turned it on, restarted my Mac, and everything is back to normal 
I already have a lot of settings in BTT, and somehow today my keyboard backlight turned off because the battery ran out, and I panicked when it didn’t turn back on 
OMG, I spent hours on this, I thought my keyboard was broken.
I want to ask, could this be the cause of my issue? There are many device names with the same name. Basically it’s the same device, but because of errors or not responding, I’ve had to re-pair it many times, using Logi Bolt or Bluetooth.
Thank you for your support, Andreas 
This one:
