Bandar Pahlavi was linked to a supply depot instead of a rail depot because there was no rail link to the port during WW2. However, supply depots only have supply level 2 and the unload button required supply level 3 to be lit. I created an exception for supply depots.
Please try out this file (it's also supposed to fix the issue with spawning units when Egypt surrenders and land unit deployment to airfields):
https://www.dropbox.com/s/re2p0wcl2upzm ... class?dl=0
Game.class should be placed in the game folder under your game installation folder. Remember to backup the old game.class first.