In my games they're also buggy. The most irritating one being that the crystal icon vanishes when a starbase is built so you can't find them again because of the fog of war. ie, you spot ascension crystal 800 parsecs away and ignore it for now. Then when the Iconians claim it you can't find their starbase to blow up without a hoard of scouts to find the crytsal that's "over in the top left corner" you saw forty turns ago.

I also had a game go fruity when I purchased ascension starbases from another civ. The bases awarded crystals to us both. Saving and loading seemed to clear that up, but it crashed soon after so I gave that up and restarted.