Playing on a 1440p monitor, I've set UI scale to 1.5. 

I noticed this setting also affects how far you can zoom out while playing. On UI scale 1, I can zoom out and see the whole map, but on 1.5 the zoom out is limited so the top and bottom are cropped out of view.

Interesting! I wouldn’t have guessed that zoom would be affected by UI scale. I’ll take a look, thanks for the note.