For the Vault Cards' Manufacturer-related challenges, grenades don't count?

For the Vault Cards’ Manufacturer-related challenges, grenades don’t count?

I have a "Kill 250 enemies with Hyperion weapons", and while my Widowmaker grenade mod counts for the Galaxy Manufacturers’ Challenge of Business Bombadier: "Kill enemies with Hyperion grenades."

They don’t seem to be counting for the Vault Card? Or is it because Widowmaker’s a strange one? It has multiple different possible manufacturers, and the initial grenade is not what kills?

I lob a mine, which, on explosion, turns into homing rockets?

I wonder if it’s similar to how Zane’s Duct Tape Mod is said to protect Zane from his own guns and grenades, but the Wiki seems to indicate that’s incorrect somehow?