Basically, I'm moving a unit with 6 cargoships (6 units embarked) towards the west. At the first enemy island there were no problems with selecting units and disembarking them (same as all my other random games).
However, when I load them back up after capturing the island (they have good AP and supply) and move further west to capture the next enemy island, the units will not disembark from the cargo ships. I can select the unit and the highlighted disembark button, but no disembark hexes become highlighted. The disembark hexes I'd like to unload onto are a "fields" and a "plains" with no apparent enemy units present (checked it out with destroyers going up to the shoreline....shouldn't I be able to unload directly into combat against an enemy unit if there was one there? i.e. a city). No one wants to attack this larger island.
Testing this, I tried going from the first captured enemy island and instead went north to land on the enemy mainland which is the same distance away from the first island as the second island (but, closer to where I originally came from). There is no problem (with or without a headquarters unit on the cargo ship unit) disembarking onto the enemy main continent. But, that's not where I want to be.
I've tried changing headquarters for the cargoships to shorten the range from HQ to cargoship (don't see that as an issue though if the ships have enough APs and supply), also to not have them connected to the 4th headquarters in a chain (just trying possibilities), and held the cargoships just offshore for a turn to have more AP when they pulled up to the shoreline.
What am I not not doing right/considering (I'm not the strongest naval rules person)?