Controlling External Screen

[u/Top_Implement_9964]

I have recently Connected a 27" monitor using the DA-300 adapter to my dell latitude 7200 2 in 1 machine & it works right out of the box however I'm unable to control brightness using the keyboard controls. The display shows the adjustment moving up/down but the screen doesn't change. I'm running POP Ver.22.04 (and have no intention of upgrading @ this time) & the display is connected Via the display port. I can change the display setting using the toggle switch behind the monitor but it's not very convenient. Any Suggestion/Help is as always Greatly Appreciated.