Sometimes when I first start playing, the little > icon on the minimap and full map screen wont be there. When it's like that, when I die, the icon for that doesn't show on the map, either. Usually they'll show up once I've died and respawned, though..
Yep, happened to me a couple of times. It will still not show if you enter a vehicle or turret but will appear after a respawn or two.