There appears to be an issue currently with SiriusXMs servers. You might check the ‘View real-time status’ link, or any of the already existing threads about this issue. 

And, having clicked on the status page, I see Sonos is suggesting it has been rectified. Not knowing the specifics of what went wrong, or how SiriusXM fixed the issue, I would suggest a reboot of your router, followed by a reboot of your speakers.