Hi. 

I’m not an iOS user but check out Upcoming changes to ‘On this iPhone or iPad’ Playback (https://en.community.sonos.com/announcements-228985/upcoming-changes-to-on-this-iphone-or-ipad-playback-6826585) It is the third most replied to forum topic, sadly.

Did this happen after and update?

@Jules_9 

Thank you for reaching out to the Sonos community.

The ‘On this iPhone or iPad’ feature had been removed for some time now. I recommend that you follow the link that User933635 has posted for you. It will provide you the necessary information regarding the removal of ‘On this iPhone or iPad’.

I also would like to let you know that if you have any Airplay compatible Sonos speakers, you will be able to send the music from your iPhone to your speakers.

Appreciate the reply… here’s the scoop, I understand the Apple comparability issue. They don’t often play nice with a lot of partners. I see it on the IT enterprise with a lack of parity with MSoft products and Apple. 
 

Two items and I appreciate a reply:

1. I’ve spent over $2k on Sonos gear. It’s not ok to list alternatives like uploading all my music to another third party application service just to play music on my phone. That’s not why I spent the money for Sonos. 
    
2. Only two of my more recent speakers are Airplay compatible. The other speakers in my my living room ...all 4 of them, are not. Not cool. Also when I tried to use Airplay on those that are compatible I get enter Airplay 4digit code. No idea what the code is. Regardless this would mean I would be living with Sonos playing in a Hybrid state for me to play songs on my phone...some with Airplay and some without. 
    

As customers we bought Sonos in large part for sound quality and ease of config and use. Part of that contract was to easily play music from our phones to the above market price Sonos speakers. IMO this is part of your brand and business model. 
 

No longer being fully compatible with iOS is going to hurt if it hasn’t already hurt you business. 
 

I’m hoping Sonos position is that they are actively looking to remedy this situation. 

@Jules_9 

Can you confirm that you are Airplaying from your phone to the Airplay compatible speakers while the non-compatible speakers are grouped to them?

I also would like to know if you have any other Airplay devices because, in my experience, I only come across the Airplay code when Apple Tv is being used.

Not sure if this helps, but usually the AirPlay password that you are referring to in your quoted post here is often set in the Apple HomeKit App Settings from the main home screen.See the screenshot attached of the toggle button which activates it.

That said, I have seen this password appear in the past on iOS without it being set by a user… a problem with iOS and bonjour multicast, I suspect, but toggling the switch off and on again should hopefully sort it, or maybe try a reboot of the network router to prevent problems with bonjour multicast packets on the network.

Hope that assists.

I don’t have Apple TV. I’m not using AirPlay for any devices. 
 

The other devices are in my “Living Room” which is not detected in the attached. Only the AirPlay capable speakers Master Bedroom and Basement are seen and both require the password. See attached. 
 

Thanks Again

That’s still an Apple dialog box, not a Sonos dialog box. You may want to check on an Apple site? Honestly, the first thing I would try is a simple hard reboot of the iOS device. You could try a power cycle of the speakers as well, but I really don’t see that doing anything, since they’re just simple receivers of the AirPlay 2 signal, which isn’t yet being sent by your iPhone due to that pop up.