android/app/src/main/java/com/fabledsword/minstrel/player/MinstrelForwardingPlayer.kt

@@ -218,6 +218,14 @@ class MinstrelForwardingPlayer(
     override fun getPlaybackState(): Int =
         if (isRemote()) Player.STATE_READY else super.getPlaybackState()
 
+    // Mirror remote state so any consumer that gates on playWhenReady --
+    // notably MediaSessionService's foreground-keepalive checks and our own
+    // onTaskRemoved -- sees the remote renderer as the source of truth.
+    // Without this, swiping the app away with Sonos playing would stop the
+    // service, kill the poll loop, and leave Sonos orphaned.
+    override fun getPlayWhenReady(): Boolean =
+        if (isRemote()) remoteState.isPlaying else super.getPlayWhenReady()
+
     override fun release() {
         pollJob?.cancel()
         scope.cancel()

android/app/src/main/java/com/fabledsword/minstrel/player/MinstrelPlayerService.kt

@@ -176,7 +176,11 @@ class MinstrelPlayerService : MediaSessionService() {
 
     override fun onTaskRemoved(rootIntent: Intent?) {
         val player = mediaSession?.player ?: return super.onTaskRemoved(rootIntent)
-        val activelyPlaying = player.playWhenReady && player.playbackState != Player.STATE_ENDED
+        // player.isPlaying is overridden on MinstrelForwardingPlayer to return
+        // remoteState.isPlaying while UPnP is active, so a swipe-away with
+        // Sonos playing keeps the service (and its UPnP poll loop) alive.
+        val activelyPlaying = player.isPlaying ||
+            (player.playWhenReady && player.playbackState != Player.STATE_ENDED)
         if (!activelyPlaying) {
             stopSelf()
         }