Why when I summon a vehicle on the planets, Sparrow is the only one that shows up for me to ride. I don't even have Sparrow active, I have others that I have as active, they never summon at all. Is this a bug or something I don't know about or missed? I'm at level 20 and completed the story. This isn't the ship in orbit, this is the one you summon on the planets to get from points to points, why do I have to ride a Sparrow when I have others in this same group, but they will not summon on any planet? Thanks.