Hi @rickrock47
Welcome to the Sonos Community!
You absolutely should be able to control the volume (and other settings, though full functionality has minimum software requirements) via the app.
I recommend a reboot of everything involved, though feel free to try one at a time until things work:
- reboot your router by switching it off for at least 30 seconds
- reboot your speaker by switching it off for a moment - wait till WiFi is up-and-running before powering back on if doing it all at the same time
- reboot your phone
If none of that helps, please try resetting the Sonos app - Settings » App Preferences » Reset App » Reset. Close the app and reopen it. When asked, choose to Connect to an Existing System, and log in with your existing account.
I hope this helps.