iBook & iCloud don't sync

Hi...

All my books in iBook are in iCloud.

- The books I purchased via iBook Store are all syncing as they should. No problem.

But:

- The books I purchased from other shops are in iCloud but they don't sync as they should:

a) The books don't get in to my iPad and iPhone if I don't sync manually with iMac

b) Books don't move to wished folder in all devices - if I don't sync manually

Anybody who have the same problem and a solution?