Hmm, Edge was one of the browsers I'd tested against to check that stream playback and the basic access page with the html5 audio player would work. Firefox, Chrome and the IE version on Win10 were also checked (just to cover the obvious cases I've got already installed).
I know that AAC based streams won't play in Edge but MP3 streams should be ok if using the browser page. Firefox is the only one that does it for me on Windows despite not being noted as a supported html5 audio format. Otherwise not knowing what the playback support is on the Xbox, you might need to use the direct stream url.
If you can let me know a bit more about how you setup the stream (probably best to send that via pm) and I'll see what I can work out as to why it's not working.
-dro