this is a general problem that usually does not matter the most, except in one situation.

right now, as i type, i have an invader in my prison, walking into my warden.  the invader cannot reach the battle trigger.

this can also be a much larger problem, depending on dungeon layout, as it could prevent servants from feeding themselves or bathing.

suggestion for quick fix:  move the battle trigger to the invader entering the room.

suggestion for better fix:  do not have every character target the center of a room as their destination.  or, add a check to detect if the destination coordinates are blocked, and quickly generate an offset so that the movement action can complete.