Try rebooting your router and phone.

If that doesn’t help, try wiring one of your speakers (not a Sub or surround) directly to the router with an ethernet cable.

Thanks . 
I will give that ago , can you tell me why when I add them it adds to its own Sonos network but Then try’s to connect to my talk talk WiFi (this fails) but where is the Sonos network as they still cannot be found even tho it’s tick 

obviously I need to try Ethernet cable , just wandered where the Sonos network it located as it’s not in my setting on my phone nor on the app 

SonosNet is not a discoverable WiFi signal. 

Is it possible that you accidentally setup the new units as a ‘new’ system, rather than adding them to your current system?

I clicked add product it finds it after I reset the Sonos adds to the Sonos network (whatever that is as I can’t find it on my settings) but it won’t connect to my internet for some reason (not had a problem before ) I did manage get one set up but changed the room name then it disappeared. I not sure if the app is playing up as my beam sub and 2 play ones are missing from app even tho they are working through my tv . 

oh right so What is it then ? I’m trying to learn about this system sorry if I sound a bit stupid 

SonosNet is a hidden wired and/or 2.4Ghz wireless (in-built) mesh network, exclusively used by Sonos products that supports STP - The spanning tree protocol. 

It’s not something you will normally see to connect your mobile device to. 

It’s initiated by wiring one, or more, Sonos devices to the LAN router. The routers DHCP server handles each Sonos device IP address, some of which are proxied in some instances.

Sonos ‘portable’ products (Move/Roam) however, do not use the SonosNet mesh system, but use the local router WiFi instead (2.4Ghz or 5Ghz WiFi bands). 

To switchover all ‘non-portable’ Sonos devices in a system (household) from SonosNet (wired) to the local router WiFi (wireless), you ‘usually’ need to uncable all Sonos devices from the LAN and the system will then use the trusted local WiFi network SSID/credentials instead, that you should see in the Sonos App ‘Settings/System/Network/Manage Networks’ area. These credentials are stored on each Sonos player. (The Sonos App is just a remote and amongst other things, views information stored on the Sonos products)… and so if changing router etc. the SSID/Credentials can easily be changed/updated (when wired) using the ‘Update Networks’ feature, available in the same area of the Sonos App.

Anyhow, here is a Sonos support document that outlines the features of ‘wired’ SonosNet and ‘wireless’ modes that can be used by a Sonos System/Household.

https://support.sonos.com/s/article/3235

Hope that assists you with the understanding of your Sonos System.

Ok thanks I understand weird thing is tho I didn’t connect them via cable to the router but when I set the new system up after a reset it finds them connects them to Sonos net then try’s to connect to my internet then says may have to switch on then off to find . Well I’ve done all that and they’re nowhere to be seen and since trying to set the new play ones up I’ve now lost a beam sub and 2 play ones from my app (even tho they work through the tv as normal , I just can’t play music through them as they have disappeared I’ve never had them just disappear from the app before like this I also have a roam and that gone now also 

If you are using an iPad/iPhone I sometimes see them get bent out of shape and do illogical things. Force closing the controller usually helps. Occasionally, I need to uninstall the controller and fetch a fresh copy from the website. This is not disruptive because all important details are stored in the players.

Are the ‘missing’ Sonos devices listed in the Sonos App ‘Settings/System/About My System’ and do they each have IP addresses allocated to them?

@ITC,

If all the ‘missing’ Sonos products are listed in the ‘About Box’ and it’s a controller ‘discovery’ issue, as mentioned by @buzz and you are able to ‘ping’ the missing devices, showing that they are present on the LAN (subnet), then maybe something in the detail/info. below may help you to find an answer to your discovery issue…

The discovery of the Sonos products by the Sonos controller is a slightly complex area to explore, but briefly… 

SSDP (the UPnP simple service discovery protocol) is used to initially discover the Sonos players and is done via multicasting via UDP to 239.255.255.250:1900 and, for good measure, broadcasting to 255.255.255.255:1900. 

Thereafter communication is unicast.

Both the Sonos players and controllers must share the same network subnet. However if the Sonos devices are connecting to multiple access points, the recommendations (from myself) are that they be set to the same WiFi channel and channel-width. This is for optimum performance particularly in groups and for some reason with mesh-based WiFi systems, it appears some will work okay with Sonos, but others may not, particularly if the satellites/AP’s are perhaps auto-selecting their own WiFi channels …and to help solve any issues arising, many here in the community often suggest using SonosNet (wired mode) for Sonos device-discovery/communication instead. 

In Sonos Networking my understanding is a packet can be sent to:

• A single host - Unicast - (TCP and UDP)
• All hosts - Broadcast – (UDP only)
• A group of hosts – Multicast - (UDP only)

Broadcast messages are not sent through routers, but multicast messages are.  

Quite possibly in your case, the router SSDP multicast used to discover your Sonos speakers is ‘perhaps’ sometimes not working as it should be. However I’m not certain of all the detail of your present network setup, but maybe (just for test purposes) try to ensure ‘all’ (Sonos products and controller devices) are using the same (router) wireless access point and WiFi band, if that’s practicable?

Note, that network switches (if applicable) can also have a role to play in device-discovery issues too and perhaps are not correctly forwarding the multicast packets across the LAN. Just check if any of the missing devices link back to any particular network switch and see what happens when the switch is bypassed.

See this useful link aswell (worth a quick read) re: IGMP snooping: https://community.fs.com/blog/what-is-igmp-snooping.html

It is also worth trying/fixing one of the three non-overlapping WiFi channels 1, 6 or 11 on the local router 2.4Ghz WiFi adapter, just to see if one of the channels may work better for you (but that’s assuming no Sonos products are wired to the LAN). Note too, that the SonosNet channel (when wired-mode is being used) should not be the same as the chosen router channel.

Another important area to explore is the controller device itself. Temporarily disable any security/software on the mobile controller as that can impact on discovery issues, for example, I’ve seen some users mention ‘Private Address’ (MAC Spoofing), or ‘WiFi calling’ VPN/Firewall/Antivirus software etc. which has caused them some Sonos device-discovery issues… disable these features temporarily to see if that helps.

Some features built into routers can also be problematic, three that spring to mind are ‘QoS’, ‘Airtime Fairness’ and ‘Parental Control’ - I would choose to personally disable those features, if present.

I would also check for any router firmware updates or, as a last resort, maybe consider switching the router for a different brand, or model, otherwise you may just encounter the same ‘discovery’ issues from time to time, no matter what you try to do with your wired, or wireless, devices.

I’m really sorry for the lengthy post here, but maybe something mentioned above may help you to resolve the matter, if indeed it is a device-discovery issue?

the play 5’s and the surround set up I have are in the about my system even if they are not in app . However if play 5’s gone from app once I switch them off and on they reappear so all good there 

it’s the new play ones and

play 3 I’m struggling set up they get found and added to a Sonos network but my network fail to find it maybe a network issue . I brought these other Sonos for my barn which il be using a 4g broadband sim so il try up there next week I was just testing them out but can’t get them added to my system. But il have a read through Ken’s post (thanks for that ) I’m sure il find some help there 

Just to clarify when you see the Play:5’s in the App ‘About Box’ do you also see the Play:3 and the new Ones’s in the same list too.. and also, on the occasions if/when you do see the new Ones in the App do you also see the Play:5’s in the ‘About Box’?

I’m just wondering if you may have accidentally created two separate Sonos Households under the same Sonos account rather than adding the new speakers to the initial system? If that is the case then that’s easily solved, but first perhaps let me know what you are seeing in the ‘About Box’. A screenshot or two may help too.

Yes my previous added items all there and as it should . The play 3 and 5 play ones I brought after a reset finds them plays a chime tick added to Sonos network then tries add to my talk talk but fails they aren’t in my about my Sonos . 

I think you may have possibly ‘split’ your Sonos system into two Households.

Perhaps try these steps..

• Power off your new ‘Ones’ and Play:3
• Open your S2 Sonos App and ensure that you can see your Beam and Play:5’s 
• Factory Reset your Play:3 by following the directions in this support LINK
• When the status LED is flashing green on the reset Play:3, in your Sonos App goto ‘Settings/System/Add Product’ and follow the onscreen instructions to add the Play:3 device to the current system, giving it a new room name (whatever name you prefer, but not the same as your existing rooms ‘Living Room/Family Room’.

Let me know if those few steps get your Play:3 to then appear alongside your other devices Living Room/Family Room in the App. 

And as if like magic it’s suddenly disappeared from the app . I’m ready to smash it lol

Can you perhaps ping the current missing device (Living Room) to just establish if it is still connected to the network subnet and establish if it is just an SSDP ‘discovery’ issue?

Have you checked if Airtime Fairness/QoS (if applicable) are disabled within your router configuration pages and checked the various other things that were mentioned in my earlier (lengthy) post, such as disabling ‘WiFi Calling’ and ‘Private Address’ (MAC Spoofing) etc.

My personal initial thoughts are that it’s more likely the router/AP configuration you’re using for the Home network… but thats a guess without knowing the detail about the local network subnet.

stupid question but what do mean by ping ? Just check the app now and the play 5’s have gone and the beam sub and surrounds are back . Maybe internet going down do you think ? If I switch the play 5’s off then on they reappear but play 3 is lost can’t play anything through play 3 

This is what it said in app when I did connect play 3 and I could tick the box I assigned it to the office in the app but won’t play 

everything else is working fine all be it the disappear and reappear by magic 

Can you perhaps describe your network hardware. Make/Model of router, wifi access points, switches etc.

Edit: What Sonos devices are wired, if any?

It’s a talk talk router only a few months old we have super fast fibre with them no Sonos devices are wired all WiFi connected everything in the house sky q is all WiFi and works great we also have boosters and further points in the house 

what do you mean by ping the Sonos press play do you mean ? I’ve tried that no joy 

Pinging a device:

https://www.alphr.com/how-to-ping-an-ip-address/

Anyhow as you are using Sky Q mesh - see the advice/suggestions in this Staff post:

https://en.community.sonos.com/troubleshooting-228999/troubleshooting-sonos-on-wifi-6856334?postid=16520976#post16520976

Here’s an extract taken from the Staff post linked above…

In the UK, Sky Q boxes can be a challenge with Sonos, as they repeat the WiFi from a Sky router (not from other routers). If a speaker connects to one of these (common with Sonos Home Theatre products) it can result in the speaker being missing from the Sonos app. To get the speaker to show in the Sonos app, you need to disable the 2.4 GHz broadcast of WiFi from the Sky Q box(es). You can go into the Sky Q’s engineer’s menu (highlight Settings, press 0,0,1, then select Settings), go to Network and toggle 2.4 GHz wireless to OFF then click Confirm. If you do this make sure you leave the 5 GHz on so that the boxes can connect to each other. As with above (in 5 GHz section), you’ll need to split the bands to differently named WiFis in the router’s settings. If you have Sonos devices that are willing to use 5GHz (see above, under 5GHz band), you may not be able to bypass this issue without using SonosNet.