the Tomb of Um 2 doesn't state it sends Dragon bones to the focus storage only Baby dragon bones and doesn't send them to the focus storage when toggled and worn
The Tome of Um 2 should send bones, big bones, baby dragon bones and wyvern bones to the focus storage when toggled and worn.
Are you saying it's not sending baby dragon bones, or it's not sending dragon bones? If it's the latter, that's intended.
Or are you saying it is sending dragon bones, although it's not supposed to?