Melee Strike Werewolf form skills do not build combo?

Tempest Bell requires combo, combo is defined as being built by successfully striking enemies with melee hits from any weapon or BODY PARTS from other skills than the combo required skill. Therefore Tempest Bell SHOULD build combo from werewolf lunar assault or shred skill as they are tagged as strike skills and are melee using "body parts" but it is not receiving any combo.

Is this a bug or is this a proper game function? Would like some clarification.

you lose combo on weapon swap, had a mace/quarterstaff build ran into same problem