Occasional disappearance of item when transferring using shift key and click

I have also had this bug but I have not been able to reproduce it either, which is why I haven't posted here yet. For me, I had a chest that was full of random junk on my first playthrough when I didn't know anything and a Pog came and started digging the chest. I tried getting into it and just managed to open it really quickly then the Pog continued to empty it. Afterwards if I shift+clicked items to move them between my backpack and normal inventories, it teleported everything I tried to move to said chest. But I have no idea what causes this bug.