When I change the resolution to something other than my default desktop resolution (1080p) In the game settings, my entire desktop changes to that resolution and I have to manually change it back (after every single play session)
For example, if I change the in game resolution to it's default 800x600 resolution and than exit the game; now my entire desktop is displaying in the games 800x600 resolution. Does anyone have a fix for this please??

Add "xrandr -s 0" (no quotes) to the end of your launcher script (start.sh if you're using gog's).

Wow, thanks! I can't believe that worked. I'm not familier with changing code so I expected to do something wrong but nope. Thanks it changes back to 1080 every time I exit the game now. I wonder why they can't update the game to add that line of code to it...