Roger's Digital TV list still has all these channels. Looks like they removed these channels only in Ignite side.
Are you saying you are seeing something different from the link I provided on Digital TV and/or IgniteTV? If so, please advise. I'm not sure how the Sonos works, but as you say, when it "reboots" you may only see the channels that you're supposed to on whatever TV package you're on.
As stated earlier, if you use the Stingray app on a device like phone, tablet or the Stingray website on a computer, you will have access to all of the Stingray channels, along with artist/track flexibility, etc.