Since the last update, 21 days ago, newly placed loaders are not working, they do not load any trains. Existing loaders, placed before the update are working just fine. Only new loaders, while placed the same way as the existing ones don't do anything.

Can you send a save game?

I'm having a somewhat similar problem. I'd send a save, but the save is huge and has many other mods. The loaders were working fine up to when I tried to build my latest station. Here's a pair of screenshots:
https://i.imgur.com/lavAC8c.jpg
https://i.imgur.com/POWHVzr.jpg
The first one doesn't work at all, it just stores up the material. The second one I built a while ago and still works fine.

I love the mod by the way, it's an absolute game-changer for my railway based factory network. Really great work.

Your first one is loading plates. The second one is loading ore. Can you double check the mod setting from inside the game (esc -> settings -> mod settings -> map) and verify that the BRLs are set to allow either “ore+plates” or “any?”

Looks like that was my problem, thank you. Turns out this is the first one I've built that isn't loading ore.

It seems to be working just fine now. Apparently with the update it had in game be set to only ores while the overall mod setting still was ores and plates. I had only checked the overall mod setting. But thanks for the fast reaction.

The option from Main Menu -> Settings -> Mod Settings -> Map affects only new games. That’s not BRL specific but how that menu works for all mods.

To change settings for an existing map you have to do it from the in-game options menu.