Spotify Connect stopped working on AV receiver

[Jds225]

Plan

Premium

Country

 USA

Device

Samsung Galaxy S9+

Operating System

Android Pie

My Question or Issue

My AV receiver stopped showing up as an available device (Denon AVR-X6400)  after the most recent Spotify update.  It's not listed on my wife's Galaxy S9 either (same OS and app version).  I have a friend with a Spotify connect enabled in AV receiver and it didn't show up as an available playback device either (also a Denon). The receiver is listed as an available device on my daughter's and friends iphones. My Firestick and Chromecast are still available and working properly.

I verified that my phone is connected to the same network as the receiver. I reset my receiver and I've performed a clean install of the Spotify app on my phone.  

Is it a bug? Are Denon receivers no longer compatible?

Please help.