are fluid train cars able to store dark matter residue?

[TorJar_Fluffyboi]

I'm trying to automate synthetic power shards but the train doesn't seem to wanna put dark matter residue in the fluid train car, even though in the train schedule it says you're able to load it and unload it off the train, I suspect this is a bug but I'm not sure.

[Paragon]

Yes

[TorJar_Fluffyboi]

omg I put it in the output instead of the input. I'm so tired