I sometimes find when back on my home network that Symfonium has trouble accessing my Emby server as I have set my external hostname as the media server source.
I’ve also been playing with Navidrome and tested a few Subsonic clients, in those clients I noticed an easy option to set local IP and local SSID (or option to set if local is preferred) so as to avoid issues when on local network.
Would it be possible to add this as an advanced option on the media source as I much prefer your client overall and the ability to transcode to Opus with Emby as the source?
Sorry no plans for that Google have decided that reading SSID requires precise location permission and that permission does not fit a music player app.
What most people do is either have a router that support reentrant NAT (Most do) else use DNS views to return different IP depending on when they are on their LAN or outside.
With the benefit or using your own DNS server to block ads and tracking.
If you really do not want to do anything, just add the 2 hosts inside Symfonium with the 2 IP and enable the option only online provider and it will auto filter on the proper host
Symfonium is smart enough to share the image and offline files cache between the 2 hosts.