I certainly would not keep factory resetting the speaker as that is quite unlikely going to resolve your issue. What state is the speaker in at the moment? What is its Status LED showing after you power on the speaker?

Check that your Beam is not showing in the App as having (missing) surrounds - if it does, then try to remove the surrounds, or consider resetting that product, but only as a very last resort.

Next power off all devices - including both the router & mobile device and bring them all back online one at a time in this order…

• Modem/Router
• Mobile controller device 
• Wired Sonos Devices
• Wireless Sonos devices  (nearest first)

Let each device settle and connect online, before moving to then power on the next Sonos device and the next etc.

Then when all speakers are present and showing in the Sonos App, go onto add the problem One-SL speaker to the system via ‘Settings/System/Add Product’ (that’s assuming it’s already in a reset state and has a flashing green status LED after powering it on).

See if those steps work for you.

Hi Ken

Many thanks for your reply, I will try this properly after Xmas, as at least I have the beam and sub working properly, don’t want to waste and more family time on this - just some further information the offending speaker is on with a solid white light and and is listed in “about my system” in the app, but in system products it has a red dot saying not registered 

anyway thanks again 

Andy 

In that case, If you click on the wrench next to its name in the Sonos App (Settings/System) and follow the instructions on screen, it should lead you through completing the setup and registering the speaker. 

Hi Ken

I have many times, just keeps going through the sequence and then some old - cannot link to your account - product not registered ‍♂️

Andy 

I assume it’s the S2 App you are using and that the mobile device meets the requirements shown HERE? …if so then try logging out the Sonos App in Settings and sign in again …and after doing that try following the wrench to setup the speaker again.

Hi Ken

Ive been through everything still no joy, and to cap it off the Mini Sub disconnected and after reconnecting it won’t register, Sonos wants me to make adjustments to my hub, however the first step I did (changing modes ), disable all Wi-Fi connections so I couldn’t see my S2 app, I have explained that it was all working ok before disconnecting and we have cctv home security cameras and not prepared to mess with its settings, so I’ve requested to send my products back to my original supplier for full refund.

I’m so disappointed because when it’s works it sounds fantastic, however I’ve lost complete confidence in the Sonos System, I feel if this is solved the next problem is just around the corner, it’s caused no end of arguments with the wife, it’s only 8 weeks old and being self-employed I haven’t the time to keep messing with the set up.

sorry to go on, anyway many thanks for you help

kind regards 

Andrew 

Ah OK - sorry I was not able to assist you further. Have a great New Year.

Hi Ken

Just a update - after sleeping on it went back to basics and with some more research it’s all working great now.

Factory reset everything - turned all Wi-Fi devices off - disconnected all devices - turned off 5GHz on the hub and rebooted hub.

Starting with the boost I connected each speaker one by one letting each one settle.

I think my problem was the 5GHz on the hub and a Wi-Fi extender in another room for the cctv.

It’s all behaving well and back to its brilliant best.

Thanks again and a Happy New Year to you.