Sonos device throws Internal Server Error when using playurl

Hello there.
So I got my brand new Sonos device and already tinker around with it.
For context: I have a Raspberry Pi 4 4GB with OH2 and Mycroft installed. I want to tell Mycroft to play a song via Soundcloud. He should resolve the query to a link and post it to OH2 via MQTT. That part works flawlessly.
Then there is the part with OH2. I managed to get OH to send the link to my Sonos device but there is the problem. The Sonos throws a HTTP 500 straight into my face. In specific it is code 804 which was inside the SOAP Envelope.
Does anyone know what this means for me and what I have to change to make it work?
Thank you!

PS: A Soundcloud stream URL looks like that: ID)/stream?client_id=(Client ID)

http 500 is defined as “Internal Server Error”.
Does the same url work from your browser and the command line using wget or curl ?

In the browser it works. I haven’t tested if the same applies to wget or curl but it should work. I have researched a little bit myself too and found out that the API URL just gives me a HTTP 302 (Found) to the CloudFront CDN. Could the issue be that the Sonos device can’t handle redirects?

Edit: I have tested with curl and wget. curl just shows me the redirect and wget even downloads the file.