Players with starting shelter near a military outpost are screwed. Turrets are slowly creeping towards the shelter in attempt to eradicate the player. Also note zombie soldiers are innately hostile, see you from a mile away and move together with turrets. Turret movement speed isn’t high, but it certainly isn’t static either.
I have had this problem as well but with laboratories where after i killed the first turret, i came back to that same evac as another survivor and a new turret was there but just to the right.
Confirmed in 0.4
This is a long-standing bug with the way things get stored when they go off-map. It happens with friendly turrets, too, and can do some really weird stuff.