Having exactly the same issue. Thought I was going crazy. Haven’t raised it with tech support yet as I am still struggling with a dropped speaker after reconnecting my system to a new modem/router. Not happy.

There are a couple of things here.

First, if you’re having trouble connecting to stop playback from your controller, that suggests some difficulty with your controller reaching the speakers in order to send a command. I’d recommend trying a reboot of your router, it won’t hurt, and may help.

Second, since the Sonos system doesn’t ’play’ from the controller (it plays from your device if you’re using Bluetooth, but then you’re not using the Sonos controller, but some other app), it won’t stop when you turn off the ‘remote control’ on your phone. Much like your TV doesn’t stop playing if you take the batteries out of its remote. 

If the reboot of your router doesn’t solve your issue (and I’d be tempted to reboot the phone, as well), you should submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

Thanks.  I tried both of those steps, to no avail.  I called Sonos tech support yesterday, and was told my wait time would be 80 minutes.  They also had no call back option.  So no luck there - I didn’t have an hour and a half to wait on hold. Good products, but terrible software and customer support.  

I’m having the same problem; I can connect to my system, but can’t stop or control playing music. Restarting the app does nothing.  They’ve really broken what was a great system

Also same problem— connected but won’t play from library or. music services

Ever since I updated my Sonos app I have attempted to switch the radio ( usually) off about six times before it goes off. This never happened with the previous app. It’s very annoying:-( 

Tried all the above to no avail.  Finally gave up the ghost and unplugged all Sonos equipment in the house.  With the number of good sounding portable Bluetooth speakers nowadays, I plan just to just use small portable Bluetooth speakers where needed.  No more headaches without the bulky hardware and non functional software