This is a very old bug that occurs when u load saved games with 3 or more players. I already report that in the past but no fix was realesed.
How to reproduce the bug:
Start a match with 3 or more players
After few turns save and close the game
Create a new game, wait for players join and load saved game or revert to autosave
The bug consist in Lackey mark zone visibility wrong after load a saved game. I already test and see that bug in Windows version using VTES plugin, don't know if also happens in MAC or other games.