Spotify Connect Issues with Marantz SR5009 & Arris 1682G Modem/router

[bulldog777]

After Comcast replaced my old modem with a new Arris 1682G I have begun to experience problems using the Spotify Connect feature on my Marantz SR5009 receiver. 

I have been on the phone with Marantz and with Comcast (the ISP) multiple times trying to diagnose the issue, but so far haven't found a solution.

After plugging in and powering on all of the devices after replacing the modem, Spotify Connect worked for a few hours. Thereafter, the option to connect to my receiver disappeared from the Spotify interface on my phone and my Macbook. 

I can solve the problem by disconnecting the Marantz receiver for ~30 seconds and then plugging it back in. After this, Spotify Connect will work for a few hours before disappearing yet again.

Occasionally, I'm not able to connect Spotify to the receiver at all. I open up Spotify, click the devices icon, see the SR5009 icon, click, and the icon shows "connecting." The receiver will look like it's trying to connect before ultimately failing to do so. 

This situation has become immensely frustrating. I've called everyone I can call and reset / reinstalled everything multiple times. Spotify is the primary provider of content I use for my receiver, so getting it back up and running is essential. 

Thanks in advance and hope someone has a good solution for me!