Hey there @menobodyknows , thanks for bringing this to our attention. That's really unusual that you wouldn't get influence points back by destroying the ships and culture buildings you'd built with them.
Can you make sure to verify your game files for me? This makes sure that nothing went wrong when you updated your game to the new update. Here's our guide showing how that's done.
If you save your game, and then basically get rid of everything you should get influence points back for, do you get anything back at all? Or is it only ships and cultural buildings?
Also, if you try building a new ship with influence points, and then selling it, do you get the points for that one back?
Thanks for your help with this - I'll keep an eye out for your response