OK, I have an answer - you will need to re-add services using the NEW phone app.  When you do, the services will show up in the web app.  There doesn’t appear to be a way to add a service using the web app (yet?)

I found many of my services missing too, so got on the phone with Sonos. They could see all my services registered - it seems there is a bug in the new app/web app that omits some of the installed services at random. Using another device with the old app installed I can see all of them. The guy in support did not know a way to fix this without removing and re-adding everything so I am holding off messing with things until they fix it.