PDFs not syncing across devices

I am using the Adobe Digital Editions to sync ebooks that I have borrowed from the local library across my devices. All of the ebooks are syncing without issue, but when I create another library and upload pdf's or other ebooks into my libraries they are not showing up as options to sync on my other devices.

I have authorised all devices and it is definitely working with the ebooks borrowed from the library. I am using the mac version of ADE and haven't had any other issues with storing pdf's in the application.

Any help would be great!

Cheers!