Did you follow the instructions for a new router or did you do something else?

https://support.sonos.com/en-us/article/connect-sonos-to-a-new-router-or-wi-fi-network

Hi Stanley

Thank you for your message. 
I have tried that several times without any luck. 
It is only the new WiFi that is visible in the Sonos app and the app says that it can see the Sonos speakers but cannot connect. Any idea of what to do?

Thank you 

Maybe try resetting your controller?

https://support.sonos.com/en-us/article/reset-the-sonos-app

Looking back at your first post, did you mean you did a Factory Reset?

(Never do that without calling and talking to Sonos first.)

https://support.sonos.com/en-us/article/reset-your-sonos-product

If that is what you did to all your Sonos at one time you wiped your system and will have to start from the very beginning.

If that is what you did you need to start over.

https://support.sonos.com/en-us/article/add-a-new-product-to-an-existing-sonos-system

Hi,

Once again thank you for your help.

I tried to connect to the new wifi through a different iphone. And it worked on the same type of iphone as mine. After setting all speakers up I tried on my own iphone and I still have the same issues. 

So everything is working fine, except for my own iphone. Any idea of what the issue can be?

Thank you

What stuff do you have loaded on your phone that wasn’t on the other? VPN, filters?

Compare the settings between the two too, you might have some option selected causing the issue. Can’t help on Apple stuff as I’ve been avoiding them for many, many years.