My SiriusXM service works fine through the Sonos app.

Have you tried removing the service and reinstalling it? Resetting the Sonos app? Restarting your phone?

I am having the same issue. I have removed and reinstalled Sirius. Re-verified and all channels are still greyed out.

Then I would recommend you call Sonos Support directly to discuss it.

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

I have called customer support and the rep had no idea and suggested coming to this forum. 

Odd. Since you haven’t bothered to tell us what steps you have tried, or what suggestions Sonos support had you check, this community is likely to suggest lots of things you may have already tried.

Without further information, I’d suggest a few things, with no guarantees. First, check your account at www.sonos.com to ensure your account is set up with the appropriate address. It’s a long shot, certainly, but worth checking. 

Next, perform a network refresh, by powering down all your Sonos devices, and reboot your router. Give the router a couple of minutes to come back up before plugging back in your Sonos. 

I’d also check in your Sonos controller for any software updates, or firmware updates for your devices.

I’d also be aware of any port blocking, such as VPNs, work profiles, pi-holes, or virus protection that might be blocking access to the SiriusXM server(s). 

I did the steps mentioned in the first post. Everything is updated, router has been rebooted. I have a feeling it is because I have S1 equipment, but the Sonos technical support did not say anything about that being the possible issue.