I would like to share with you the solution to a problem I have been facing for a long time, and it made me extremely unhappy :)

I like to use the f.lux feature where I use keyboard shortcuts to change the brightness of the screen using ALT+PGUP, ALT+PGDOWN.

About half a year ago it stopped working for me, and today I finally found out a solution.

My setup:

• Lenovo laptop T14s
• USB-C Docking station
• 2x Dell 27" QHD Monitor connected using display port to docking station

So what you need:

• Latest displaylink drivers
  https://www.synaptics.com/products/displaylink-graphics/downloads/windows

• Run Registry editor as administrator.

• HKEY_LOCAL_MACHINE\SOFTWARE\DisplayLink\Core

• Create a new key of type string with name "EnableGammaRamp" and value "true".

• Disconnect the USB-C docking station from the PC, wait a few seconds and reconnect

• I've also re-run f.lux application.

• That's all :)

ALT+PGUP, ALT+PGDOWN is working again.

Live long and prosper.

M*