I experience some problems when I try to stream some music from my Raspberry Pi 3.
On my Pi I have a MP3 file and a NodeJs webserver with some routes running on port 1234.
When I open https://localhost:1234/play in the Pi's browser, I can hear the MP3 playing.
Also, accessing the server from a different computer in the same network does work, e.g. calling https://192.168.1.42:1234/play from my notebook's browser.
Now I also want access from outside my home WiFi, so I registered for a DynDNS service, configured my Pi and the port forwarding on my router. Making some REST calls to the NodeJs server also works in this case.
But streaming the MP3 is NOT working. When I open https://sth.dyndns.com:1234/play I hear the music playing for less than 1 second but nothing else.
Neither the server nor the browser shows any errors in the console. In the network tab from devtools I can see that the request is still running and its status is 206 - partial content, which seems correct.
Any ideas? Could my DynDNS provider be the reason? Or router settings?
Thanks in advance and best regards