We bought three of these boxes to bake the cookies, 3 of my Zois put one of them in their inventories.
Jeb had been able to bake his, but after that, the other two boxes vanished from the other 2 Zois inventory, they are also not able to bake them (should they have unlocked the receipe somehow)
I tried to reproduce this bug in my old / fully updated Dowon save file.
The boxes don’t despawn from my zois’ inventories when one of them bakes any of the cookie variations. I can confirm that neither of them learned either their own baked recipe, nor any of the others’. I’d really prefer if they learned them once baked.
From what I’ve seen, you just need to have one of the boxes in your inventory to bake the appropriate recipe. I don’t know why they would disappear from the inventory though.