f.lux not working on Monitor through a USB-HDMI cable nor through an Adapter

[Nick V]

Greetings,

Recently, my main Surface Book charger stopped working and it costs a heck of a lot, so I switched to an older charger that has a USB-c connection. That meant discarding my old USB-C to HDMI cable that I used to connect to my monitor.
I opted for a USB to HDMI converter that I thought would work fine, which it did, except for the fact that the screen brightness remained constant even though I was changing it in f.lux.
I thought it might be a converter issue as the USB-C was working fine, so I bought a regular USB to HDMI cable and the problem still persists. Could someone please elaborate if they had the same issue before, and maybe if there is a fix for this?

Additionally, I have no HDMI connection in my PC and at the moment my only USB-C port is taken by the charger. I could in theory get a USB to USB-C adapter, but I'm afraid I'll run into the same problem.

Much appreciated.

Nick