Update seems to have fixed this since last night. Not sure what was going on. Disregard I suppose?

https://mods.factorio.com/mod/Krastorio2/discussion/5eaa13cf06db07000c88aa1d

Says it all.

Krastorio 2 'uses vanilla' implementation of loaders, which are not in the game.

Imagine loaders:

> Loader 1 : Filter A (say, Iron Ore)
> Loader 2 : Filter B (perhaps Coal)
> Loader 3 : No filters set ...