Board Game Arena

Have just been tying to use this. Expanding o the port givs me a messae "an only be used duing a trade action"l if I ordr a "sell" for the unit the action happens immediaeely, so I don't get the adjuskment!

OK, answer discovered. Ordeer the trad as usual and the option to adjus is offered auomatically (providd you can afford it!)

This does not work for me. I Have access but never get asked to use it. Also that behavior seems bad i. General. I wanted to make a trade the requiered the action to be affordable but that was impossible. Did another trade instead but did not get asked to use the port

While its not the most intuitive, I never had any issue with it. If I look at your last game from your perspective, I can buy and use the port in all legal ways I can think of.
I even get suggested to use it when trying to buy for more than the money available:
"Buy 2 Cheese for 12 each? 20-24 = -4 You don't have enough money, try using a port"

Then I can use the checkbox to use it.