Issue description
Trains just sit at the station, not loading unit cargo. Loose cargo works fine.
Also looks like unit cars are trying to load two separate item types.
Reproduction steps
See train at station for unit pick up.
Two item types get assigned to first car.
Car does not load items.
Game version and build number
v0.8.8b (b631)
Which branch of the game are you on?
Stable
Operating system
Windows