Firstly, gonna request a sticky for this if I can get it.
Anyways, I encountered a problem where my cursor would work perfectly fine if I had to move across the globe/map but when it came to having to move it in small increments, it would get 'stuck' wherein it wouldn't move as smoothly as it would with large jumps.
After about 20-30 minutes of searching, I finally found the (easy) solution.
So if you have this issue as well, proceed to your control panel. Go to hardware, then mouse. Pointer options. Then disable 'enhance mouse precision.'
Should fix your problem. Just thought I'd share this fix for any fans of the old DOS games. This fixes this problem across all the old DOSBOX games.