Chromecast Icon only appears at local web 127.0.0.1

[Lego]

Chromecast icon only appears when i'm at the local host web-app and using the 127.0.0.1 address. Windows 7
It will not appear using the Windows hostname in the Chrome address bar, or the local IP address, or other hosts pointing to it - though i can use Subsonic in all of those cases . I have Premium subsonic
I think (127.0.0.1 access only) this is a clue to the reason why i'm not getting Chromecast function on other devices. Bur where that clue leads, i dont know, which is why i'm here. Firewall is disabled and I've removed anti-virus. Any ideas? thanks!

2. Even at 127.0.0.1 webapp using Chrome When i click the Cast icon to the right of play arrow - music play stops, and the Cast icon has color as if it is casting, but nothing is playing.

My Chromecast audio network is fine, VLC plays to it like crazy,This is a fairly new, and first install of Subsonic on this computer.