Spotify problem on Marantz 5009 and iPhone

[jeiff]

Hi All,

I have a Marantz 5009 connected by LAN as well as 2 HEOS speakers connected by WIFI to the same network. All is controlled by iPhone also on the same WIFI. iPhone sees all the devices in the Spotify App and I can select the devices to play on.

The problem starts when I try to go into the Marantz 5009 device in the Spotify APp and i.e. change the volume or select another device. Marantz immediately stops playing and I need to select it again and press play. Volume control doesn't work at all. This doesn't happen on any of the HEOS speakers. 

Any ideas/suggestions are welcomed?

Many thanks

Rafal