S50 Pro+ HTTP API playing some URLs and not others

Hey folks,
I am experiencing some oddities with the http api for the S50 Pro+, It started with me trying to diagnose why my HomeAssistant setup won’t play google TTS, and it seems that the S50 will play some URLs using

httpapi.asp?command=setPlayerCmd:play:

but not others. And I can’t figure out why.

I’ve tested some random mp3’s I have found online. For example,

https://www.hyperion-records.co.uk/audiotest/18%20MacCunn%20The%20Lay%20of%20the%20Last%20Minstrel%20-%20Part%202%20Final%20chorus%20O%20Caledonia!%20stern%20and%20wild.MP3

Will not work, while https://filesamples.com/samples/audio/mp3/Symphony%20No.6%20(1st%20movement).mp3 will.
Interestingly, https://www.soundfishing.eu/download.php?id=245 will work, but https://www.soundfishing.eu/download.php?id=245%20dd will not, even though the latter is still a valid url

Is there a pattern for which type of URLs can be played over the httpApi? or is there redirect/connectivity considerations I’m missing?

I can’t quite figure out what is going on here. Hosting the same google TTS mp3 on my local network does not seem to work regardless of the domain it is reachable at. The follow do not work:

Even though these are reachable by all devices on the network.

However the same file hosted publically at

  • https://nextcloud..com//download/test.mp3
    Does work. Which suggests that:

  • It’s not to do with the file

  • It’s not likely to do with the complexity of the URL(?)

  • It may be due to the connectivity of the S50 to the hosted server? Even though the device should be able to reach the file at any of the above locations.

Following up here for the sake of posterity and to hopefully to get some insight as to how the S50 fetches media over wifi

I’ve managed to get this working by hosting the media at a device which is accessible at an IP:Port address.
For HomeAssistant, that means I’m setting the local network configuration to this IP:Port combo.

This IP:Port routing is also managed by Traefik, so for all intents and purposes it behaves the same way as a domain backed by an A record would. so the only outstanding question is: Why doesn’t the S50+ Pro work with the domains I’ve tested locally? I’d love to get more info on how the device is resolving addresses for Wifi streams