Chromecast Spotify Connect on Windows app

[studioloft]

Hi there! When opening Spotify on my Android phone I can go to the Spotify Connect tab on the bottom and select a range of Sonos, Google Chromecast, Chromecast Audio and Google Home Hubs in my house to connect to.

However in the Windows 10 application when I click on the Spotify Connect button I only see the two Sonos devices avaiable. On the Android app I have the Sonos plus the Chromecasts.

My question - How can I get the Chromecasts avaiable to cast to from the Windows application? I am assuming this is some Windows firewall setting?

Currently I have to start a playlist on my computer then open my phone in order to transfer the playlist to the Chromecast Audio (in my stereo). A followup question - if this is not possible is there another device than the Chromecast Audio that I can use to get my Spotify on the Stereo short of running a direct wire (not an uption)

Thank you!