Spectator & Charm of the Diva do not work in other Baubles slots (only Amulet)

[Shahelion]

Using version 1.13.4, there are no particles when sneaking near dropped items, or when holding an item that is nearby, or anything.

[Shahelion]

Turns out it only works in the Amulet slot. If allowed to go into another slot, such as Head or Charm, it stops working. There are a number of baubles that are like this.

[Shahelion]

It also doesn't seem to see any items in the offhand, which is a separate issue perhaps.

[Shahelion]

Charm of the Diva has the same issue.