From Sonos:

Lock screen controls will not appear in the following scenarios:

• A non-Sonos AirPlay capable device is present.
  • Disable the AirPlay feature on all non-Sonos AirPlay endpoints to allow lock screen controls to appear when using Sonos.
• Another app on the device is playing music or video.
• While connected to a Bluetooth audio device.
• VoiceOver is enabled.
• Headphones are connected to the iOS device.

I have to disable AirPlay on my Apple TV and Roku for the Sonos controls to show on my Lock Screen.

Thanks for your reply. I had seen this advice and I believe I have met all these conditions and I still don’t see sonos on the Lock Screen of my iPhone. I believe I need to turn off airplay on my iPhone but can’t see how or where to do this. 

When you bring up the list of available AirPlay devices on your iPhone, do you only see Sonos devices or are there other non-Sonos devices on the list?

Ah right. Thanks. Just Sonos plus the sky Q box. Not sure how to turn off airplay on that and what the consequences might be!

The consequence would be AirPlay is disabled on your Sky Q, but you will now have access to the Sonos controls on the Lock Screen. If you ever need AirPlay on your Sky Q, you can always enable it again.

Thanks. Tried turning off the airplay on sky Q. That worked so …. I could see Sonos on the locked screen. Great. 
 

BUT … lost all capability to adjust or mute the volume on the tv! So that’s a bit useless. 
 

My TV is a Samsung and I use a Sonos playbar for sound. The sky remote is programmed to control the volume on the Sonos playbar. 

I’m not sure why or how disabling AirPlay on the Sky Q would affect the Sky Q remote’s ability to control the volume on your TV/Playbar. But if this truly is the case, you’ll just have to decide which is more important - Sonos Lock Screen control or Playbar volume control using the Sky Q remote.

Me neither - totally baffling. Thanks very much for taking the time to reply.