A fellow Roonie and Sonos user.
Are you able to play music via the Sonos app. Check the volumes before you do and lower to a minimal level. Then play something.
Also, are you using Sonos Streaming or Airplay with Roon.
Double check you haven’t accidentally set volume to fixed in run on all the Sonos devices.
Check Roon’s volume for each is set to minimal.
It sounds from what you’ve wrote that your volumes were at full.
Are you using an iPhone as a remote also. If so what iOS version is it on.
Regarding the lost control issue, have a read here.