I upgraded to BIAB 2016 and I also have the updated iOS app for BIAB. However, I am having the same issue with the BIAB iOS app on both the iPhone 6 and the iPad.

I deleted the app and re-installed it. I then connected to the BIAB server and downloaded all the songs again from the BB2GO folder. On the app, these songs are highlighted in green, indicating that the rendered versions are on the mobile device.

But, the rendered (downloaded) songs won't play as they used to do in the previous versions. It appears that the updated program won't allow the ios app to play downloaded songs without being connected back to the BIAB server. This stinks! Please help.