If it displays correctly using 1920 x 1080 than that suggests that the native aspect ratio is 1.77:1 If you change the monitor to 1920 x 1200 than its aspect ratio is now 1.6:1 Depending on how the code was written, the GUI can be stretched, but visual spacing is bound to suffer somewhere.
Also, my SmartSDR is v1.10.16. I have had no need for the functions in v2.
You NEED to add the Napoli font to your monitor driver. Just add the font to your font library, here is the zip file to download and expand.
You will find this discussion at this Community listing.
This should fix you up ..
Thanks for great support as always!