I never saw something like this! everyone want to know how to move a starbase but what that I find that it's moving itself!
so it was the last moments of the game and I had a lot of Freighters because I commend them to go to "Kona" and the U.P issue of a limit of trade routs told me that this is to much Freighters. But the Freighters I had are not the COM Freighters it was my own designed Freighter that I called him Trade Ship. so I didn't know what to do with all that ships So I clicked one of the ships, and I pressed the "Upgrade" button. I upgraded all my Trade Ships
into Constructors, but I forgot that I have trade routs with trade ships with it but I said "no matter". and then in the next turn I saw all my trade ships as Constructors, and they all had the ability to "build starbase" so I said: "what the?? Let's press the build starbase button!" so the next turn I had a star base! on the trade route! and I thought it can't move! but he moved as normal trade ship! on the trade route. I think it's a bug but you can try it out!
this is what I saw: one normal starbase and one "Trade Ship Starbase"