I am struggling to get UPnP search working with MinimServer at the other end. I don’t seem to be the only one to have this issue:
https://forum.minimserver.com/showthread.php?tid=5594&highlight=upnp+search
Has this functionality been disabled in Volumio?
EDIT: I just tried UPnP search using BubbleUPnP and MinimServer and it works like a breeze.