That’s odd, I don’t think I’ve ever seen a controller turn on itself and run. 

Do you have notifications turned on, and are playing music on one of your Sonos speakers? Or perhaps some sort of alarm fir playback going off?

There’s no reason why you can’t delete the application itself, and download a fresh version from the Google store, and install it. Just be sure to ‘connect to existing system” when presented the option. 

No, the app is turning on even if the speaker is powered off. Initially I thought it may be only happening when I'm in range of the same network as the speaker, but it's occurring even when I'm in a different location than the speaker. There are no alarms set up in the app, and I've never used that feature. I will give the fresh install a try, but wanted to see if this was possible something others had dealt with before trying that.

I've tried a fresh app install, but in addition to not resolving the initial issue, I've started receiving an additional warning. I've not encountered it before this, but it says the widget may be impacted by stopping the service. I'm receiving it after I've already shut the system down, and it thankfully doesn't seem to be repeating like the other one. 

Have you called Sonos support? 

No, I wanted to try this route first to see if this was something others started experiencing as well after the last update.