I'm not sure if this is actually bugged or if I'm missing something. I've switched the magnetic field so that the smallest pigeons are dispatched for the heaviest boxes, given espresso to the orange cat and tranquilizer to the white cat. Predictably, after giving a voucher to the Postbot, the pigeon isn't able to carry the package and falls. That's it, nothing else happens. I eventually gave in and looked up the puzzle solution, and apparently the above steps are supposed to result in bubble wrap on the floor. Anyone else have this problem? Is it an actual bug or am I just doing it wrong?

Thanks!