You can equip several necklaces of the same kind and be unable to unequip one of them, it seems like the game thinks that there's no necklace currently being worn so when you click on "unequip" it just equips a new one instead and you are able to unequip that one but not the initial "ghost" necklace, I've tried this in both the web page for torn and play store app, I'm on a Samsung Galaxy A51 (I have a screen recording but I don't know how to upload it, so I'll add SS where you can see several gold necklaces and several pearl necklaces equipped instead)
You can equip several necklaces of the same kind and be unable to unequip one of them, it seems like the game thinks that there's no necklace currently being worn so when you click on "unequip" it just equips a new one instead and you are able to unequip that one but not the initial "ghost" necklace, I've tried this in both the web page for torn and play store app, I'm on a Samsung Galaxy A51 (I have a screen recording but I don't know how to upload it, so I'll add SS where you can see several gold necklaces and several pearl necklaces equipped instead)