Exactly 

My issue is the app used to see my Sonos One SL and now it doesn’t. But 15 speakers ? Heavens above

Ive seen plenty of forums and comments about various types of connectivity issues. Why don’t Sonos just release the pre debacle, working, version of the app until it gets sorted ?

Appalling management

That seems a bit of an overreaction. 

I have had Sonos since the ZP days and have never had the connection issues I see people ranting about. What I did with my network was to configure it for Sonos to work while being hardwired. I have 11 Sonos devices with 6 of them hardwired. I an a believer in having a main speaker like a soundbar, Amp or Five connected, and not depend totally on WIFI because of how it is susceptible to radio interference.. So my Arc is hardwired with the Sub and surrounds paired to the Arc. A Five , 2 Connect S15s, Amp and Play 1 are also hardwired. 

Can you answer some questions that may help the community help you?

1. Do you have any speakers hardwired to your network? Sonos at onetime recommended that one speaker be hardwired for every five you have, So you should have at least 3 hardwired.
2. What type of network do you have? ISP router, prosumer products, mesh?

To be Frank Pools I don’t think any answer Wrekshop gives will be of any help. In my view and experience in losing connection to my single speaker is simply that the app has screwed everything up

The thousands of posts all over the internet prove that as well as Sonos themselves. I will cite my case of a simple single Sonos One SL on the same WiFi as the phone no longer sees the One SL. I’m in the uk and with Trooli fibre but obviously on WiFi for the speaker. 
my router sees the speaker as being on WiFi. But the app refuses to find it. But it did before the update of a few months ago that started all this

Check your router supports mDNS (Multicast) ‘Device Discovery’ - it might ‘perhaps’ be a simple settings change that’s required. What make/model of router is it? Do you have an online link to its user-manual?

Hi @Ken_Griffiths, I don’t believe there is such a thing as an mDNS setting in consumer (or pro-sumer) routers. Both mDNS and SSDP rely on multicast, which is a switching function.

So isn’t IGMP Proxy, or Snooping, needed on some routers?

As an example too @press250 - I’ve seen users mention that an ASUS RT-AC86U ROUTER needs iGMP Snooping to be enabled for efficient multicast forwarding - but I don’t use that router so I can’t test that here. My own router has no user-accessible settings that I can change.

I see from this link though for Ubiquity Unifi, that requires some changes ….

https://github.com/IngmarStein/unifi-sonos-doc

…just as examples.

Only if you are trying to implement a fairly advanced setup, specifically performing multicast across subnets. I know this from experience about six years ago (documented somewhere in these forums!) getting it to work* with all of my Sonos devices on my “IoT subnet” and my controllers on my “humans subnet.”

In short, only some foolish enough to attempt an advanced networking setup (cough, like me, cough) would encounter a situation needing a multicast proxy.

* Here’s the painful irony: after running the gauntlet and getting everything working smoothly, I realized that such a bespoke networking setup could work for years … only to break when something shifted … at which point I would have forgotten 99% of the lessons learned. So I went back to an ‘approved’ setup with devices + controllers on the same subnet. Live and learn!

I think it might be IGMP snooping that’s required actually - isn’t the proxy only needed when the devices are upstream?

I just recall that some routers needed the IGMP Snooping setting enabled - I have that Asus model RT-AC86U for example in my own notes here, where that resolved ‘device discovery’ issues and it was disabled by default, IIRC.

You see where I said that was six years ago? And where I said I would forget 99% of the lessons? That’s where I’m at now!

IGMP snooping is a switching function that optimizes multicast traffic, well, so there isn’t as much ‘casting’ going on.

IGMP proxy is a routing function, as I touched on above, across subnets.

I will just briefly mention here too, that also some other settings on routers can cause problems with Sonos devices, including ‘QoS’ and ‘Airtime Fairness’ and on Ubiquity Routers, these settings need to be disabled apparently for the reasons stated…

• Multicast and Broadcast Control - (blocks all multicast and broadcast for non-listed devices).
• Multicast Enhancement (converts multicast to unicast when possible).
• Client Device Isolation (prevents wireless client on the same AP from communicating with each other).
• Proxy ARP (converts broadcast to unicast when possible).

… again that’s just from some notes I have taken from other community posts here in the past.

And just to add if a user still isn’t able to sort these things, or they perhaps don’t work, I would certainly go onto refer them to Sonos Customer Support in the end anyway to hopefully help them to get their issues resolved. I’m just trying to assist those that post looking for help here in the community.

ha ha - I’m still learning, for me every day is a ‘school day’.

Sorry Ken I didn’t mean to sound testy and ungrateful. Not a good day. 
 

Apologies, your advice was appreciated

No need to apologise - I do understand the frustrations. Some of us with working systems are just trying to assist - you’re not alone with venting at some of us and at Sonos. Sonos say their working on putting things right so some things suggested in the community threads might perhaps assist in the interim.