Sack lunch can't be put in school bag or lunch bag

Recently we had an SDX drop with more swatches for the school bag and a new lunch bag. Also the school bag became an item that can hold other items. You can drag something into it, and then you can drag the school bag into the sims inventory.

However I experienced that sack lunches, that came with Parenthood, can't be dragged into the school bag.

It can still be dragged into the sims inventory directly but I think into the school bag is more realistic.

I'm a bit disappointed by this and feel like EA should make this possible.