I have been having the same issue--on my iPhone, I could not access any of my music services, nor could I log in to my Sonos account, though I could see all my speakers and start/pause them (but not choose what they would play). After a lengthy back-and-forth with the Sonos support team, and a phone call today, I found this thread and decided to see if I had a VPN going on my phone without my knowledge. Turns out I did--ExpressVPN had activated itself without giving me any indication of it--so I turned it off and all started to work again. 

How frustrating that must have been! My previous company required a ‘profile’ be installed on all devices that could connect to the email servers. What they didn’t explain was that ‘profile’ included a VPN, which took me a while to figure out, so I feel your pain. 

I have the same problem.  I have two Sound 1 speakers playing in stereo. I was controlling them via a Pixel 2 XL. Last week everything worked perfectly. This weekend, all of a sudden certain services are not available on the phone controller. There is a message about signing in but when I try to do so I get a “Network problem detected” message. I have a router for internet and two range extenders, one on each floor of my house. The basement extender is hardwired to the router. The upstairs is linked to the basement extender via wifi. I have rebooted everything - router, extenders, speakers, phone. I still get the message. I can easily control the speakers from the controller on my laptop, including insuring I am signed in there. All services are available on the laptop controller. But on the phone, no luck. However, when I  change stations from the laptop controller, the change is reflected on my phone. Any help appreciated. 

@snitramc sounds a lot like you had a VPN added to your phone, maybe to connect to your work network so you can work remotely? VPNs will usually mess with local network access.

As everything works from your laptop, the problem is on your phone somewhere.

Hi,

i have read through the whole of this topic as I had exactly the same problem causing me no end of confusion. Then I saw the dreaded VPN word and realised this was what was causing the issue.

i use Norton secure VPN. Norton keep telling me to enable it so I did but it causes a LOT of issues with many apps including my sonos.

so, what’s the point of personal VPN on my iPad if it causes apps to fail or not work properly?

thanks to all in this forum for solving my issue quicker than I would have otherwise.

Wouldn’t it be nice if Sonos took this problem seriously? I’ve been torched with the same issue for several months now, no resolution at hand.

The music services and sign-on refuses to work on my iOS device (iphone Xs iOS 13.3.1). Windows controller works fine. Using a visitors iOS device works fine. So obviously the problem resides on my  device itself, but nobody has been able to pinpoint it, including Sonos Support.

Yes Cisco Security is installed but only Umbrella which should not be the issue (have also tried removing it, to confirm that). Furthermore I don’t use a VPN on my device in general, so that doesnt seem to be the issue either.

Fresh ideas appreciated! 

@dwi1972 

I am having the same issue on iPhone XR iOS 13.4.1

I looked at the Cisco support link above and Cisco says:

“This issue will require a resolution from the Sonos side. Please contact Sonos support to add your support for a resolution.

Cisco Umbrella has investigated this issue and confirmed that all DNS queries received by the CSC are answered without issue when the impacts occur. As a result, the issue is confirmed to occur in the OS layer between the DNS request and the transfer of this DNS query via the NEDNSProxyProvider Network Extension in iOS to the CSC with a component of the Sonos system currently in use.”

Has there been any response from Sonos to this?

Glad I found this. I have a business phone with Cisco on it. 
 

Luckily I have an iPad so not an issue. 

My iPhone was getting the same network error while all my other devices were not.  I have “Circle” installed on my network.  It’s a firewall to monitor my kids internet.  I turned off circle and it solved the issue - I was able to log into my sonos account.  When I turned circle back on, I’m still logged in.  I disconnected my iPhone and sonos from the Circle network to be safe going forward.  

Yes, had same problem on Android, wife’s iPhone worked fine. Turned off ExpressVPN then it worked fine. Then re-activated ExpressVPN. 

I had experienced the same issue despite of iOS version. Discovered that it was company VPN Zscaler that was blocking the Sonos app. When the Zscaler is disabled the Sonos app works just fine. 

For me was the opposite, I had to enable connection via Surfshark to be able to access the internet. Y power cycle everything with no result. So, since I se everyone disabling the VPN and I do not have those enable, I tried to enable it to see what happens, and it worked.  Usually I had this error with all my devices OSX, IOS, and android.  with the VPN  it works now. I will talk with my internet provider to see if they can fix the issue.