Odd, if traps are found I find my characters are unable to trigger them, even if all 4 almost stand on top of it.
Of course unfound traps still trigger as normal.
I haven't been religiously trying to trigger traps so maybe it was just a pathing issue. Could have been I was already clicked to move to a spot and detected the trap as I was still moving, thus never altering the pathing. Maybe if I clicked after detecting the trap the pathfinding would have taken it into consideration.
