When the loader is vertical it will not load items into the wagon.
When horizontal it works correctly.
The unloader works correctly in both orientations.

Factorio version 1.0.0
Mod version 1.0.5

Double check your alignment. The loader must be aligned such that the selection box that you see when mousing over the loader is centered over the wagon.

Because BRLs are very tall, this is not the same as centering the sprite.

Wow, how did I mess that up. I must be blind or something.
Anyway, thanks mate.

I totally missed that too. I thought something was wrong.
Great mod, thank you.