I have an issue with my courier not supplying carrots to pig farms, wheat to cow farms and seeds to chicken farms. I have my couriers trying to deposit carrots, seeds, and wheat in the bottom of the perspective farms. So far they will not deposit them.

I have had the best luck depositing the items in the front facing side, depending on whatever direction it faces.

Each farm as a "Sides" button.
You can see the defaults, and define more usable sides from that screen.

Closing works correctly in 1.12 and likely was just configuration issue as suggested.