When I choose "no loader", the baggage train arrives, stops for some seconds and then drives away with the baggage still on it. Do I miss anything?
Do you mean "no loader" in the parking customization ? If yes, that's normal, but in general is wrong configuring something that should always be the same because is related to the airplane, in the parking.
Usually, the no loader option should only be used to disable ONE loader on that particular parking spot, because there's no space for two, but it assumes an airplane that normally has two loaders.
We don't have loaders that go lower than the ones available, ideally there should be a completely different animation of bags loaded manually, but is just not there, might be something for a future update.