One thing I have noticed is that the AI can capture any number of outposts in a single turn. So, if the AI wins a battle and I have three outpost in a system, it can capture them all on that turn. I however, only seem to be able to capture one at a time. If that is an advantage for the AI, no big deal. I just want to make sure that I am not missing something that would allow me to capture more that one outpost at a time. Thanks!
Yes, it's a known issue. It should only be able to take a settlement at a time. This should be a rare occurrence. In any case, this has high priority and we'll see what we can do for the next update.
Though, I would think more important than fixing this is to make the AI more efficiant at capturing and defending outposts. Regardless of difficulty, at the end of the war I pretty much always own all the outposts. I have never seen the AI defend an outpost (maybe because my ships are too fast) and it does not enough to retake them. This makes the game trivial as even if I loose a planet or two early in the game because of the difficulty level, I still come out of the war stronger...
I have stopped contesting outposts because I know I can just wait a few turns and take it back without a fight.