Hi I Installed Zorin 17.1 on 21.5" 2014 imac and there is no brightness control for the display. Night light (color temperatrure adjust) and Dark mode are different,
Prior to installing 17.1 I tested the machine on 16.3 from USB loader and the brightness control was there .
BTW it boots direct into Z17 . There is no mac OS as I formatted the internal drive hoping Zorin would install on it, no dice. I have installed on a external 1TB SSD via USB3 & it runs quite nicely. except for the brightness bug.
Its same on wayland or xorg
here is a screenshot showing missing brightness adjust slider
screenshot
thanks .. Don