Hi @Florisdeman 

Welcome to the Sonos Community!

With one phone connecting, and another failing to connect, we have to look at what’s different about the phones.

One possibility is that your girlfriend’s phone is connecting to a WiFi booster or extender while yours is not, or it is connecting to a different Access Point.

I think it more likely, however, that some software installed on your girlfriend’s phone is blocking access - I know there have been some issues with Microsoft Defender recently.

Please also be aware of the following:

I hope this helps.

Thanks for you reply Corry. We both use an Iphone with the latest iOs. Couldn’t find any difference in settings between the phones. It still is a mystery to me. Probably a factory reset of her phone will do the trick…

Hi @Florisdeman 

Is your girlfriend's iPhone a privately-bought phone, or was it supplied by her work? If the latter, it may have extra security functions configured that is blocking it from accessing Sonos on your local network. Your girlfriend is unlikely to receive permission to change this.

If the phone is privately-owned, however, I strongly recommend comparing installed apps - my opinion is that a factory-reset of the phone is over-kill, and if the same apps are installed on it afterwards there’s a good chance that it won’t make any difference, so would be a lot of work for nothing.

One more thought that may help: please ensure that the use of the Private MAC Address function is disabled on your girlfriend’s iPhone for your network: https://support.apple.com/en-gb/HT211227

I hope this helps.

She has a privately owned phone and just checked our settings, everything is the same.

Problems still persist. 
just found this tread:

This really sounds like what is happening to my girls phone, but strangely I don’t have the problems

Hi @Florisdeman 

Does your girlfriend’s iPhone have the same subnet as Sonos? Your Sonos system is on the 192.168.2.X subnet and if your girlfriend’s phone is not on the same, she will not be able to connect.

Please open her iPhone’s Settings page and tap Wi-Fi, then tap the information icon (i) next to the network she’s connected to. Here, you can see her local IP address. The first three parts of her IP address should be 192.168.2, and if they are not, that is the main issue. If this is indeed the case, then it likely means you have two devices on your network configured as DHCP servers, which is not good. The fix is easy, however - just follow the instructions to put your Linksys mesh into Bridge/AP mode: https://www.linksys.com/gb/support-article/?articleNum=316730 for Linksys mesh routers, or https://www.linksys.com/support-article?articleNum=243548 for Linksys Intelligent Mesh.

If this is not the answer, I recommend you get in touch with our technical support team who have tools at their disposal that will allow them to give you advice specific to your Sonos system and what it reports, before resetting her phone.

I hope this helps.

Now something interesting happened! 
I was trying to update some network setting in the sonos app and then I got the prompt to update my app to the latest version. Apparently I was still using sonos version 15.3, and my girlfriend was already in 15.4.

Now I updated to the 15.4 version, I have the same problems. I can not longer connect to my wired system…

Any idea how I can go back to version 15.3?

Hi @Florisdeman 

Well, that’s concerning!

There is no way to go back to an older version of the app (well, it’s technically possible, but you’d need the old app package download, which is now missing from the Apple App Store).

I recommend you reboot both iPhones and your router - if issues persist after that, please get in touch with our technical support team who have tools at their disposal that will allow them to give you advice specific to your Sonos system and what it reports.

Please note, however, that my previous post still stands - if your iPhone now has a subnet that isn’t 192.168.2.x, then that perfectly explains what’s going wrong.

I hope this helps.

Yes, she has the correct subnet 192.168.2.x

Hi @Florisdeman 

In that case, this is all pretty weird and I recommend you get in touch with our technical support team - but please come back to update the thread once you find out what the issue is.