I made a butch of starbase hulls, but when I assigned them to the custom civilization and then redownload it, only one of the designs makes it in. Either this happens to every civilization that uses this set of starbase hulls, or it doesn't.

This civilization has the "broken" starbase hulls - https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=3217087810

This civilization does not have the "broken" issue -
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=3417464438

This issue has been there since Galactic Civilizations III, and this is very infuriating, as I design a set of starbase hulls, and only when the custom civilization is uploaded do I know whether the hulls are hit by the bug or not. Should that happen, I end up redesigning the starbases from scratch. I suspect that it has to do with certain parts being involved.

https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=3224969251

The 'base" starbase for that faction was designed in GalCiv3, but it still works:
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=1214590038