Edge in Windows 10 Insider build 15002 seems to have a bug that affects ogv.js's streaming input, causing requests for Ogg file chunks to fail. Specifically, the 'Range' request header is being incorrectly set on the CORS OPTIONS preflight request, which naturally returns a 416 "Range cannot be satisfied" error.
Result is that audio and video cannot be played back in Edge browser on the latest Windows Insider build...
Reported upstream: https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/10494718/