Bluetooth Metadata not transmitting from iPhone 6 to Pioneer Z150BH

[Symbiont]

Hi. I noticed a few other threads similiar to this, but they were either closed or unrelated.

I have an iPhone 6 (iOS9) and a Pioneer Z150BH on the most recent firmware, and Spotify won't transmit the metadata when the iPhone is paired via bluetooth. My friend's Samsung S4 works fine over bluetooth, however. The controls work fine and it sounds fine, but I'd love to have the metadata show up.

If I use the iphone cable with the Pandora app (but play spotify instead), it works.