I have a strange problem with Chromecast Audio streaming from Spotify 7.5.0.1023 on my iphone with iOS 10.2.1

My Chromecast Audio is on and ready to cast.  I launch Spotify on my phone, start playing a song and then go to the Devices screen to select the Chromecast.  The song keeps playing on my phone and nothing happens.  Sometimes, it eventually connects but then controlling the playback from my phone is super laggy...Think 20 seconds for Skip Track to work. Most of the time, it usually doesn't connect.

Now here is the strange part - the only way I found out how to fix this is to turn off and then turn Wifi back on again.  As soon as it reconnects, everything works the way it is supposed to.  Press play, boom, it plays.  Skip, pause, everything.

I am on Verizon FIOS and have the Actiontec router.  I did change the router settings per recommendations on IGMP Proxy and UPNP.  And it does see the Chromecast, it just lags in connecting to it.

Any suggestions, or should I just disconnect and reconnect to Wifi everytime I need to do this?

Oh - by the way, I have three Chromecast Audios and this happens across all three of them.

Thanks!