Hey found the fix to this issue and wanted to share it here.
First enable Sonos from System Preferences, Security & Privacy, Privacy, Accessibility (check Sonos)
Turn the Firewall off.
Route: System Preferences, Security & Privacy, Firewall (turn it off if it’s on)
Uncheck File sharing
Route: System Preferences, Sharing, uncheck File Sharing if it is checked.
Then, if Sonos is installed, uninstall it from within the app.
Route: Click on Sonos, Uninstall
then install the newest version from Sonos website and try adding your Music Library
Sonos, Preferences, Music Library, click on +, Another folder or a drive connected to my computer,
search the location, Next, Add admin pass and voilà.
Spent like the whole day following articles and googling until this method worked. Now I am listening to my iTunes music.