[#1732][6.20] Supply Fleet order's "destination" can't be moved

[LameFox]

When you issue a supply ship a "supply fleet" order and choose a position rather than actually assigning it a fleet, the resulting order can't be dragged like other positional orders (e.g. position defence). This leaves no apparent way to adjust the height of the order since as far as I know that must still be edited after the order is created. I have tried both with shift and tilting the map view.

This is entirely consistent as far as I can tell, so either starting a custom game with a supply ship or using one in an existing game should demonstrate it.