The standard Trainz "Container Station" industry just loads containers and will not ever unload containers. It does have a track on the other side of the industry's yard that accepts deliveries of General Goods.
There is a sign over the two container loading tracks that, if it has not been edited, will say "Container Station 1" or something similar in larger black letters above the smaller blue lettering. Most of us edit the larger black lettering to a unique industry name. Someone could have put the word deliveries above the blue lettering.
The smaller blue lettering says:
"20 ft CONTAINERS PICK UP THIS WAY"
"GENERAL GOODS DELIVERIES OTHER SIDE OF STORAGE BAY"
"40 ft CONTAINERS PICK UP THIS WAY"
If this is the correct Container Station asset, it will never unload containers. No matter what the sign says.
There used to be a Seaport industry that unloaded containers, but I'm not seeing it in TRS19.