Is this on a device running Fully Kiosk Browser?
I just installed the new Sonos app and it looks like you might have to use the full path for the component as the ‘new’ app still seems to use component paths based on the old app’s naming:
The full intent URL (for Fully Kiosk Browser) would be:
intent:#Intent;launchFlags=0x10000000;component=com.sonos.acr2/com.sonos.acr.SonosLaunchActivity;end
It looks like the simpler sonos:// URL still works too. I had both Sonos apps installed and it prompted me which one I wanted to open. So it looks like you could probably pick which app you wanted to use and choose to Always use it or could delete the old Sonos app and it looks like the new version works with that short URL. 
