I just resolved the same issue. So I hope this might help. Connect your Sonos to your new network via Ethernet cable and use the Sonos app to access the settings. In System>Network>Networks remove your old network.

I was then able to follow the standard Wifi set up process.

Hope this is helpful to anyone still struggling. 

I am having same problem. Have hooked unit to Google router via Ethernet cable but still no connection. Have unplugged and reset through instructions on website.

 Never shows Sonos Network in Wifi 

I have just reset Sono One and Play 1 using Ethernet connection with Sonos One; that worked 

very fed up with Sonos Beam . Wish I had never bought

i never get green flashing light. How long did you wait b4 green light showed ?

To factory reset your Beam, you may continue holding down the join button as you reconnect the power cord for about 3-5 seconds.

Factory reset my Beam and that’s the only thing that worked!

Factory resetting is rarely a good idea and virtually never solves a problem permanently if at all.  It also destroys all the useful diagnostic info.  Please don’t factory reset.

I had the same issue, but this immediately fixed the issue for me. 

I’ve had my beam for about 2 months now, no problem out of the box and system worked amazing with my two One Speakers — but suddenly stopped working this week, doesn’t show up in app or any other streaming music services. First time I simply disconnected/reconnected power and it rejoined the system, second time not so much. 
I suppose I’ll try the Ethernet connection reset as some suggested, but this is a real hassle as my cable connection is no where near, hence buying a wireless system. Really hope Sonos recognizes this problem and can be solved with a software update down the line. 

Same problem here, Beam worked fine for around 3 months now completely invisible to the Sonos app and WiFi.  Spent a frustrating evening following troubling shooting advice on the app and via  Sonos messaging  to no avail.

I've now got to order an Ethernet cable at my expense (on the advice from Sonos) to try and resolve the issue. Not happy!

Have you rebooted your router, unplugged the Beam from power for about a minute, rebooted your phone, or reset the Sonos app under App Preferences?

Thanks for the response. Tried all those fixes, alas they were all unsuccessful 

This has also happened to me. I tried removing my play 3 also. When I re-setup my play3 it finds the network but my beam won’t

Same issue here!

Update: Phoned customer support, spent around an hour trying various fixes, including factory reset,  so lost all playlists etc. Still not resolved. Only advice now is to update my Virgin Super hub 2 router despite this working perfectly fine for over 3 months. Anything but the Beam being faulty, right.

Currently back to using an ethernet cable and since restoring all the stuff I lost back onto the app the Google voice assistant is now refusing to play any radio stations.

Patience has now run out with this glitchy device. Any advice on how to get a refund, replacement?

I just got a sonos beam and have a very similar issue. Straight out the box It wont connect to my wifi. Done all the rebooting and spent over an hour with online adviser where we used an ethernet cable which works effortlessly and then tried to change the network settings to wifi but no joy. My router is virgin super hub 3 and I have it setup for both 2.4 & 5GHz. Did anyone resolve this issue, don’t really want to waste a few hours speaking on the phone to customer support if they cant fix it.

Very disappointed in this I was expecting good things, especially as connection to other devices is one of its key points but yet a fundamental “connecting to wifi” appears to be glitchy or virtually impossible

old topic similar problem last month sonos pushed an update that crippled the beam

The problem is related to the latest update. Bogus solutions resetting router etc. Nothing works after 45 minutes question was asked do you have a android device?  This household does not have it. So apparently the development at sonos has some problems and they can’t get the iOS app working. And now we are running a treadmill resetting routers switching of 5 ghz etc.

I have 2 play ones and the new roam both work perfect! Roam on 5 ghz play ones on 2,4 this is a sonos related problem! Mann up and be honest. Say sorry and give a timespan when there is a update to the beam working again. And please hire back your iOS de developer honor your roods make it work!

Bought the beam in us when it just was released always worked. Until an update gilts 2 years ago this one is the worst update ever.

How to recognize? check the listed networks they do not change even after a factory reset.

I had the same problem and I just resolved it  

1. Connect your Sonos to your router via Ethernet cable .
2. In my case, the Sonos beam required an update which I installed.
3. Use the Sonos app to access the settings - it will prompt you to disconnect your ethernet cable so disconnect the ethernet cable.
4. Go to System>Network>Networks remove your old network
5. .follow the standard Wifi set up process for a new network.

Hope this is helpful to anyone still struggling. 

Ramesesh, I followed those steps from Sonos support and initially it connects and works. Once I unplug and move the beam to where I want it, it no longer connects to wifi even though it's not 15 feet from router. I have other Sonos devices connected without issue and this beam device has eaten 3 hours of my life with no fix. Time to take it back to Costco? 

I had this same exact issue and it was driving me nuts. Got on the phone with Sonos support and after an hour of troubleshooting, they had me check my wifi router settings. I made sure my router met the below criteria. This fixed the issue and the beam is working like a charm. 

Recommended router settings for a Sonos system:
a. Auto channel must be set to Off
b. Choose best non-overlapping channel (1,6,11)
c. Set channel bandwidth to 20MHz
d. Both 2.4GHz and 5GHz should be enabled
e. UPnP should be enabled
f. 802.11 band should be set to b/g/n
g. Airtime Fairness should be disabled
h. STP must be enabled for SonosNet setup
i. Parental controls (if any)

In my situation, i had to change my channel from 6 to 11 because channel 6 was too crowded (i live in an apartment building) and i had to set my bandwidth to 20MHZ.

Good luck! I hope this helps!