OGA (v1.1)+ EmuELEC 4.5 Brightness?

Hi,
Just got an Odroid Advance and installed EmuElec, latest version 4.5.
All good and noted from here (HotKeys for Odroid Go Advance, Odroid Go Super and GameForce Chi · EmuELEC/EmuELEC Wiki · GitHub)

"Global HotKey (HK) default is is button V (5)

  • GHK + Dpad up/down changes volume.
  • GHK + Dpad left/right changes brightness."

My volume up/down is fine using V + up/down as above but the brightness adjustment doesn’t work.
I can change the brightness via the menu but could really use hotkeys for in-game adjustment.

Ta for any ideas?