**SSDP discovery (M-SEARCH) gets no response from any player – not even player-to-player**
System: 6 devices (Play:1 Kitchen, Play:1 Bathroom, Play:1 Bedroom, Era 100 SL Office, Arc Ultra Living Room with 2x Era 100 SL as rear speakers)
App version: 88.01.10-release+20260820
Firmware: 86.8-78270 (Play:1) / 96.1-79270 (Era 100 SL, Arc Ultra)
**Symptom:**
The Sonos app (tested on two different Android phones) intermittently shows individual or even all speakers as unreachable ("No products found", missing volume sliders). The speakers are demonstrably active and ready to play – control via Home Assistant (using already-known IP addresses) and Alexa keeps working the entire time.
**Diagnostics performed:**
I narrowed this down over several days using Wireshark/tcpdump packet captures and was able to rule out all network-side causes (Wi-Fi, access points, switch/IGMP snooping, VLAN routing, firewall):
1. Test with a laptop wired directly into the same VLAN as the Sonos devices (the speakers themselves remained on Wi-Fi as usual): SSDP M-SEARCH (ST: urn:schemas-upnp-org:device:ZonePlayer:1) was sent correctly, but none of the six devices responded.
2. Port mirroring on both access point uplinks confirmed the multicast query (239.255.255.250:1900) correctly passes through the switch and is forwarded to both APs. Still no response from any Sonos device.
3. Decisive test: rebooted "Sonos Office" (Era 100 SL) while capturing. On boot it sends its own internal M-SEARCH to rejoin the household (with a proper Sonos user-agent and household ID). NONE of the other five Sonos devices responded.
**Conclusion:**
Even Sonos' own internal SSDP discovery between the players has stopped working – regardless of network path or which device is asking. All players keep sending normal periodic SSDP NOTIFY announcements (so the sending side is fine), but nothing responds to incoming M-SEARCH queries (the responder side). Restarting the app doesn't help.
I'm seeing plenty of similar reports in the app store reviews about broken device discovery since the latest update. Has anyone else seen this specific behavior (system-wide SSDP response failure, including player-to-player), or is there already a known bug report for it? Happy to share the full packet captures if useful.
