Sadly the support said, that this is not a bug. A friend of mine had the same problem and sent a ticket to the support. But you could write a ticket to the support and ask nicely if they could move the box to the intended character.
You should read the description of the fashion again. There should be mentioned, that the fashion box is not trade- and superposable. To avoid this, store the fashion box in the HEMS Mail and only take it out with the character the box is for.
