At least one item on roblox is miscatgorized as a gear item, even though it is actually an accessory.
This item: Wild Starr Guitar - Roblox is listed a gear, that requires all categories to be enabled. When worn by a player ingame, it does not show in the players starterpack, or startergear, and instead appears as an accessory on the user.
There may potentially be more miscatgorized items, in the roblox catalog, but this is the only one I can find.
Edit: this specific gear was fixed to be an accessory, if anyone finds another instance bump this thread
