I'm playing as the Romans in the Cantabrian Wars scenario with the latest Beta Patch.
The Cantabrians have besieged Gades. The port is not blockaded. I want to move part of the garrison by sea to another town. I create a "fleet" by dragging the land units I want to transport onto the naval transport unit. I plot a move for that combined unit to another friendly port. I press the "Next Turn" button: my land units are immediately returned to the garrison and my fleet sails to the plotted destination without them. Working as designed?