There should be a common denominator.
Winbox version from Mikrotik site isn't very specific, unless you provide more specific details it will be hard to help you. Latest version, 3.10
Specifically, what OS does your laptop use, and which Winbox version are you using? what about your co-worker?
what happens specifically when you "can't change" a port on a dst-nat rule? screenshots will be useful too if relevant, also specific dst-nat parameters.
Have you tried to clear cache on winbox?