Ensure you have not switched off the WiFi adapter in the Beam’s room settings, this is required to communicate with the Sub direct, even when the Beam is wired, the wireless adapter needs to be set to ‘on’.

The sub connects to the Beam via an internal 5gHz wi-fi signal.  I suspect that this is caused by wi-fi interference.

Whether this is a simple WiFi extender or a wireless mesh node, this is an unsupported configuration. There needs to be a wired path back to the router.

Wiring to a mesh primary node is permissible. Extenders aren’t supported at all. 

Note you would likely be better off reducing the system-backhaul by wiring a single Sonos device (not a surround or sub) direct to your main router and un-cabling the Beam from the Linksys extender too.

edit: Ah @ratty beat me to it. 

Except that I have had it like this on my other Sonia system for the past 4+ years without absolutely zero issues.

I think you mean with ..zero issues.
What @ratty and I mentioned is correct. If you see the below link to the Sonos ‘System Requirements’ you will see that it mentions…

1. In WiFi mesh networks, Sonos products must be wired to the primary mesh node if using a wired setup.
2. If you need to extend your home WiFi to use Sonos in a wireless setup, we recommend using a WiFi mesh router to do so.

And the following networks and devices are unsupported:

• Wireless internet connections such as satellite, mobile hotspots, or LTE routers
• Guest networks or networks that use a portal login page
• Networks using wireless range extenders (see also 2 above)
• Ethernet over Power (EOP) devices
• WPA/WPA2 Enterprise

See link:

https://support.sonos.com/s/article/126

Sorry for the spelling errors before. I was in a rush.

Thank you for your response regarding this configuration. Would you be able to explain why this is a problem that only affects the Gen3 Sub and not my other Gen2 Sub or surround speakers?. They are all connected to the same network in exactly the same manner and only the Gen3 keeps disconnecting.

A Sonos Subs does not ‘normally’ use a local router WiFi, or SonosNet signal - instead it connects directly to its ‘bonded’ speaker/main-player using either a 5Ghz ad-hoc wireless connection (which is highly recommended method of connectivity). or in some cases it may use a wired network connection if the wireless connection to the main player is inhibited by its WiFi adapter being switched off (not a recommended method of connectivity) …In the latter case, it’s always good practice to wire all players, but as stated that type of setup is not helpful in some cases, as network latency often comes into play with that type of setup.

If the first ad-hoc wireless setup method is proving problematic for you, then perhaps the first thing to look at is ‘wireless interference’ in and around the Sub and the main bonded player. Sometimes, a simple reboot of the main player can solve the situation, or simply moving the Sub closer to the main player, or changing its location in the room might sort the matter.

The reasons for the earlier settings mentioned was mostly to improve the overall network connectivity and reduce the general wireless interference, so that the SSDP multicast discovery of the players and unicast connection could be improved using SonosNet on the same chosen channel, rather than using your WiFi mesh system, which may have Hubs operating on their own different WiFi channels.

Hope that assists.

So in conclusion, would my problem be solved if I just wired the Beam directly to the Verizon FIOS modem/router instead of the extender?

Yes, the recommendation has been to wire a Sonos device to your main router, which will put all players onto SonosNet and reduce any backhaul too.. the wired device can be a your Beam, or any standalone modern Sonos device (ideally), just do not use a surround, or Sub …and obviously do not wire your Sonos products to your other WiFi access points/hubs.

When wiring a player to the router, ensure it’s at least one metre away from the router to reduce interference and set the SonosNet channel so that it is at least 5 channels away from your router 2.4Ghz channel. It’s best to set your router to use fixed non-overlapping WiFi channel 1, 6 or 11 too.

Its helpful to set your router and any access points to use the same SSID, WiFi channels and set all 2.4Ghz band connections to use a channel-width of 20MHz only.

When done and all your Sonos devices are then running on their SonosNet signal (which is confirmed in the Sonos ’About My System’ area of the App - it will show the wireless modem of each device as WM:0) ..then goto ‘Settings/System/Network/Manage Networks’ in the Sonos App and remove the 2.4Ghz SSID/Network credentials (if stored?) - If you have Sonos portable devices (Roam/Move) then leave the 5Ghz SSID and run those devices on that band, otherwise remove those 5Ghz credentials too (if applicable)… The wireless network credentials are not required for devices running on a SonosNet signal and doing these things will help to ensure your products do not ‘hop’ between the SonosNet signal and your WiFi signal.

@Shadowboricua 

I will just also briefly re-state what was mentioned earlier and that is WiFi range extenders are not an ‘officially supported’ connection method by Sonos, but some devices can and do work - but not all.

If you later find they do not operate correctly for multicast discovery of your Sonos devices in your case, then you can quickly take them out of the equation by simply changing their broadcasting SSID and (importantly) the channels they use, so that they do not clash with your router or SonosNet signals …and use those extenders for other home network devices, but then ensure your Sonos mobile controller connects only to the main routers WiFi signal.

It may not come to this being necessary in your case, but just mention it here, so you at least know where to go next if you continue to have any issues with your system.

Thanks for the answer again.

I just want to clarify that I had originally set the system on WiFi utilizing the main router signal and still had the same Sub (Gen3) disconnect intermittently. Also, in terms of distance and interference, there is barely anything around the system and the Beam 2 couldn’t be any closer to the Sub. 

Anyway, I appreciate all your help. Ultimately, this is a frustrating situation that I never had before with my original Playbar in 5.1 for the 4 years plus I’ve owned it and still have in a room which is farther from the main router.

Ok, so I went ahead and connected the Beam 2 directly to the main router. Took a lot of effort and extra money, but it is done. Only SonosNet running no wireless network “stored”.

THE SAME PROBLEM STILL OCCURS! I am beyond frustrated and I am, at this point, outside of my return period. I feel like getting rid of the whole Sonos system. Beyond frustrated at this point. Everything confirmed to WM:0.

In order to make it work I have to keep “finding the sub” every time it goes to “?”, disconnecting and connecting it, and then it comes back on for a random amount of time until it drops again!!! The sub is next to the beam. Couldn’t be any closer. And again, the other Playbar with its sub and surrounds are on a different level and has no problems!!

Purely as a troubleshooting experiment, please would you connect the Sub to the Beam by Ethernet cable. I can't remember if the Beam has one or two Ethernet ports - if it only has one then cable another Sonos device to the router to maintain SonosNet. Please let us know how this goes.

Hi @Shadowboricua,

When you lose the Sonos Sub and see the ‘?’ symbol in the Sonos App - is the Sub actually still playing the audio? If it is, then it ‘likely’ shows there is an SSDP discovery issue of the Sub by the controller device. Can you check if that is the case, when you see the ‘?’, try playing music audio or 5.1 TV audio to the Beam and see if the Sub is actually playing the .LFE channel audio.

If the Sub is working, then just go onto try these things…

Fully close (slide off screen) the Sonos App, power off the WiFi ‘extenders’ - check your mobile is then connected to your main router by toggling off/on the mobile network connection and reopen the Sonos App to see if the Sub is present and the ‘?’ symbol has disappeared. If it has, then it’s likely a WiFi ‘extender’ issue which may not always be allowing the SSDP multicast packets to discover your devices whilst the mobile device itself is connected to one of your WiFi extenders.

To sometimes resolve this issue, first of all just ensure your extenders are definitely all using the same SSID/Passwords and (importantly) the same WiFi channels and channel-widths as your main router WiFi - I recommend using a channel-width of 20MHz only for the 2.4Ghz band across all your devices.

If it still fails after checking those things are in place, then I will suggest you go back to my earlier post which provides you with the other alternative option and that is to put your WiFi extenders on a totally different SSID and channel that does not clash with either your router or SonosNet channels and to then ensure your mobile controller device only attaches to your router WiFi signal.

So in this somewhat ‘last-resort’ case, just as an example, (for demonstration purposes) your router might be put on put channel 6, SonosNet on channel 11 and you would need to then switch the extenders from channel 6 to channel 1, aswell as changing their broadcast SSID. Note: I would personally only do this if all fails in the earlier suggested setup and don’t forget to switch your mobile to connect to your router only.

Sadly, the issues you seem to be encountering here appear (at this stage, at least) to likely be related to your network setup and components, but these things are usually easy to resolve, but it just needs you to discover what network configuration may work best, as the extenders are not ‘officially’ a Sonos supported network setup.

I hope the information provided helps you to resolve the matter and I’m happy to try to answer any further questions you may have, going forward and to help you to try to resolve what I believe are possibly network configuration issues.

At this moment, I don’t have any extenders, routers, etc running. The Sonos Beam is wired to the main router. That’s it, nothing else. I am literally about to throw the Sub out the window. I am sorry, but this is how frustrated I am. Again, I repeat, no extenders, no Wi-Fi, just my main router from Verizon FIOS wired to the Beam 2. All components seem to be connected to the SonosNet. Arghh. About to sell it all.

When the question mark is ON the sub doesn’t work.

Thanks for the additional information ..in this case then, I would ‘temporarily’ wire the sub to the Beam as @John B suggested, and then submit a Sonos diagnostic report (note it’s reference) and contact/chat to Sonos Support Staff and ask them to check the WiFi radio adapter on the Sub - it’s also worth rebooting the Beam too, as that connects directly to the Sub in a bonded setup. Let’s see if the Staff can perhaps discover what the issue might be here.

If you swap your subs around, does the Sub (Gen 3) behave in the same manner with the Playbar, or does the issue move to the Sub (Gen 2) with Beam? 

I basically wired all my devices in the basement (TV, Gaming Consoles, PC, etc) and it seems like the problem stopped. A lot of work, but hopefully this took care of the issue.

I appreciate all of your help and support. Apologize for being so frustrated. Ultimately, not happy about what it took to fix the problem. Additional money and a lot of work. Hopefully, this is truly the fix.

Not fixed!!!! Omg

You are perhaps best to submit a Sonos diagnostic report (note it’s reference) and contact/chat to Sonos Support Staff and ask them to check your setup.