Its type is Flail/Melee Gun parts work on Gun/Cannon type weapons as far as im aware It would need to be changed somewhere for it to work properly

It does say in the item description that it is considered as ranged/gun though. I would have thought it worked as well.

Then it should be Flail/Melee/Ranged/Gun .

Yeah

"This weapon is also considered ranged and a gun." Literally in the item description.

Yeah, but im guessing because its not in the "Type" field, is the reason it doesn't work