This one's weird, if I understand things correctly.
Typically, we are allowed up to 20 ships in dock, correct?
I have expanded my docks to max and even have the Admiralty Connections DLC which expands dock space by an additional 10 spaces, as I understand. So, I should have 30 spaces but can't have more than 18 ships at a time or the game tells me I can't buy any more ships. Or, if I create them, I cannot teleport until I drop ships until I have 18 again (which is less than the naked game itself). I've tried exceeding 18 ships 3 times over 2 weeks, and it is always the same. The DLC is showing it is "Activated" and I have no fleets, either.