Iphone 6s-Marantz NA6005 connection problems

[Pm67]

I recently bought Marantz NA6005 streamer and connect Spotify through my Iphone 6s. Noticed two problems so far: a) while listening to Spotify twice within an hour had static noise, and b) suddenly streamer turned off completely and Spotify did the same from iphone app and when I turned  on the unit it started to play the song I heard the previous day before. Are there any known problem/bug in the app when connected between iphone-Spotify and Marantz NA6005 streamer?

[Taruskin]

My Marantz NA6005 used to work fine with my Iphone 6s plus Spotify connect, but since a couple of weeks it has disappear from the list of available devices. Even if I still can use the direct USB connexion or the Airplay, sound quality is not the same. One of the reasons I bought the pricely Marantz NA6005 was precisely its full compatibility with Spotify Connect... 

I should mention that I use a ethernet wire to connect the Marantz NA6005 to my network.