Was this ever answered? I have the same issue but have not seen my pet since. It seems that right when I placed the inventory items in, ran back to base, then the pet disappeared and was no longer linked to the pet house. I checked the house link and made sure the pet was happy before I placed the items in the pet’s inventory and now it’s either roaming around (has a helmet on) or is just gone gone… how do I find him or how do I retrieve the inventory?