Why are you standing around fleet waiting for a group?? I just picked up Mandalorian Raiders earlier while I was questing on Tatooine. That's what the flashpoint shuttles are for lol
That's what I do for Flashpoints, just go to the planet I'm questing at and it makes it really easy to find a group. We needed two more for Athiss the other day, the party leader went to Taris and we had a full group in a few minutes.