audiobook content not loading in airplay after IOS update 8.4

Audiobook maniac here. (over 250 in my library). Recently upgraded iPhone 6 and iPad to IOS 8.4. No issues with book moving from iTunes to iBooks. However, when I try to listen to the audiobook via airplay on my Apple TV, I do get a mirror of the book cover but the audio content cannot load. I have re-started/booted iPhone and iPad and Apple TV. Up until 8.4, no issues using airplay via Apple TV and iPhone 6. Anyone else having this issue?