This is the Gal Civ 4 forum and if you have your fleet on a planet starbase and highlight all the ships using the Shift key they will exit as a fleet, same with GC3. I tested and it works.
Since it works as designed it is not a bug.
I was a little abrupt with your Original post.
However with post after post of this is a bug when it is the poster failing to learn the mechanics, then instead of asking is this a bug or am I missing something? it gets tiring.
Now please go try the highlight "Shift" method and see if it works for you.