I was a bit surprised, that using the bandit with its "arse" in the delivery zone at the ramp and "unpack cargo" suddenly qualified the cabin as delievered. I assumed somehow, I was meant to use the CAT handler.

But it also works without a CAT - please note the collision model with the rope attached:
Youtube Video

Its not meant to be "played like this" - I hope.

Implied bug: The cabin there delivered was from the last contract. This one asked me to deliver TWO cabins, I thought TWO more. And not "one more to the the delivery zone".