Hi @paulz, Thank you for reaching out, and welcome to the community. Thanks for bringing this up and I know where you're coming from. About this issue. I’ll ask some questions to further check on it. 

• Are there any changes made on the iPhone before this issue occurred?
• Is there any update on your iPhone that was installed before this happened?
• Kindly double check if you are connected on the same Wifi network on your iPhone.
• Have you tried to Uninstall and reinstall the Sonos App on the iPhone?

Answers to those questions will certainly help us to check what could be causing this issue. 

Let me know your thoughts on the advice above.

The Sonos community is always here to help.

Hi Simon, Thank you for your response. Here are answers to your questions:

• (No) Are there any changes made on the iPhone before this issue occurred?
• (No) Is there any update on your iPhone that was installed before this happened?
• (Yes, on the same network) Kindly double check if you are connected on the same Wifi network on your iPhone.
• (I reinstalled a few times. Also, powered down and restarted the iPhone) Have you tried to Uninstall and reinstall the Sonos App on the iPhone?

When I opened the app this morning it was not working. I used it yesterday with no problem. I also have the app on my iPad, and that is working fine today. I have had the Sonos system for over a year and have had no other problems...and I like it very much.   -Paul

Assuming you just upgraded to iOS 14:

Go to Settings / Sonos [S1] and Allow Local Network access.

Why Support don’t suggest this I have no idea.