I wouldn’t think so, this doesn’t sound normal. I would recommend that you open up the controller, with it not showing the added services, and submit a system diagnostic, and take note of the number. Then add a service back in, start playback using that service, and submit a system diagnostic again, taking note of that number. Finally, close the controller for however long it takes for the service to disappear. Open the controller and submit a third system diagnostic, again making note of that number. Then, either call Sonos Support to discuss it, or post the diagnostic number here for a Community Moderator to pick up. Having the three separate diagnostics should be able to provide them some hard details as to how your system is changing, and help them determine why the services are disappearing.

Note, the three different diagnostics may be overkill, but in this case I think it is prudent to show change over time. 

Thanks Bruce 

I will give that a try