Enemy pawns are generally know to be very good at being completely missed by their observers. Animals - fair enough. But mechanoids want to be seen! So they can't corner one of your colonist because you overlooked them, the sneaky bastards.
Should work from 1.0 onwards.
https://steamcommunity.com/sharedfiles/filedetails/?id=2352045325 (https://steamcommunity.com/sharedfiles/filedetails/?id=2352045325)