I’m in a similar situation.
i5, GTX960, Windows 10 @1600x1200, Falcon BMS 4.33.5
After having set the game to use 1600x1200@60hz, the in game (not game UI) res is always 1024x768
Things I have tried so far:
unticking ‘Borders’ in ‘cockpit display extraction’ -> ‘main’
selecting ‘disable full-screen optimisations’ in ‘properties’-> ‘compatibility’ for the the shortcut, the executable ‘Falcon BMS.exe’ and the launcher
deleting ‘dx9display.dsp’ from ‘User/Config’Interestingly, this is also the case for 4.33.1 but crucially, not 4.33.0 - there has been a regression between 4.33.0 and 4.33.1, carried forward into 4.33.5
The workaround (for me) is to run 4.33.0 or replace the 4.33.5 exe with the 4.33.0 exe
I had the same issue with the black bars on the left and right of the screen. I fixed it following your post
unticking ‘Borders’ in ‘cockpit display extraction’ -> ‘main’
selecting ‘disable full-screen optimisations’ in ‘properties’-> ‘compatibility’ for the the shortcut, the executable ‘Falcon BMS.exe’ and the launcher