It does work on my rig with the software that I posted about.
It works because the monitor communicates with the computer via I2C.
It does not need X11 to do that. It only needs the monitor connection.
@Philippe ' s code also works on my rig.
It works because it uses X11.
It does not need anything from the monitor because it changes the RGB values that the GPU sends to the monitor.
Are you really claiming that both of these methods don't work for you although they totally work on completely different parts of your computer ?
Ok in that ddcui app try and click "view" option - I think there you should have option to switch to "Features View" - there when you open it you should be able to see that same exact options that @tkn has screenshot-ed earlier today!
Notify us if you've managed to make any progress
EDIT: also try and add this option: " Options->User Interface Options->Require control key to move sliders." -- since then you will block the possibility to mistakenly change your settings with scrolling mouse wheel - it is common to make an error when not looking where you hold the mouse when you scroll so just a precocious action
This may be a far stretch but - have you tried connecting your monitor to some other computer/laptop/anything? Just to make sure that it is not a compatibility issue or some problem with ports - because I know I had a problem with HDMI port on an old Samsung TV but when I connected it with a VGA-port it worked like a charm and later it turned out something internally messed up with hdmi port when I took the TV to a buddy and dismantled it
So yeah - do try to connect to something else and se if it works there as it should just to double check on hardware
