adobe digital edition doesnt download the ebook on all devices, ending up downloading seperately and there is no sync in them

I tried downloading a book and its not downloading on all my devices at the same time automatically. I have to download in each and every device seperately and the book is not in sync. I tried removing the book from all the devices and tried downloading it, I tried erasing the authorization and then authorizing it, I tried refreshing it but nothing works. its frustrating at this point that it is not downloading in all the devices at the same time. I have to study for my college work and nothing it working. I obviously can't use the same device to read all the time. Please let me know what I should do.