Contrast changes the display but it's not "real" for the OSD

[Theluga]

Interrogate output is here:
https://privatebin.arch-linux.cz/?bae0a4c27eaf96ec#F6gXWJUXE1T5Vwv8EUnF7NMSmXnoDq5Y9WvgQKcJZLBD

Hello! I have a Monitor from AOC model 22B1HM5-22B2HM.

I can edit the contrast by:

ddcutil --sn=WXDO4XA004311 setvcp 0x12 value

And it will work, but on the monitor OSD will display the previous value and the getvcp too will display the previous value and the command from set will also output:

Verification failed for feature 12

But the screen changes. I can see the effect of the changing of contrast. I don't know if it's a bug of the monitor or of the ddcutil.

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And a little off-topic but somewhat similar. These codes will work but it will not change the value on the OSD (the monitor can only change all values together but the command can change individually, and when all are of the same value, the monitor does not update its OSD. I believe this is a monitor bug).

VCP code 0x70 (Video black level: Blue 
VCP code 0x6c (Video black level: Red
VCP code 0x6e (Video black level: Green

Thank you for your great work and this great software!