Not possible to change monitor brightness for one of 2 identical monitors

At work I have a computer with two identical samsung monitors connected. The monitors have buttons to control brightness. On one of them I can just change the brightness normally. On the other one, when I open the menu using the monitors buttons, it will tell me this option is not available.
So I tried this answer, but it will only change the brightness relative to the brighntess set on the monitor. So I can only make it darker, not brighter.
I think this is not a problem with the monitor, but rather a problem with ubuntu and it’s settings. Unfortunately I don’t have sudo rights on the machine though.
Anyone has an idea, why the monitors are behaving like this?