I have been away from Arma 3 for a while and when I came back, Steam had updated some of my mods. When I go to play an Alive mission I made about six months ago, I notice some of the units spawn and despawn at certain points in an odd way, generally as a group of soldiers. You can't really shoot at this group and kill them as they disappear relatively fast, but it seems sometimes they can shoot back at you.

Are there any clues what is going on here? Has anybody else noticed some missions being broken by updates?