Items in the offhand slot of an Armor Stand are not dropped when breaking the armor stand

 when an armor stand has an item in the offhand slot, either with the /replaceitem command or with the help of a dispenser pointing at an armor stand carrying armor and an item in the main hand,When the armor stand is broken it does not drop an item that it had in the offhand, such as a shield is not dropped when it is in the offhand of an armor stand.