It's not Sony.
That's been removed from Android as of Oreo and now Pie.
First it was the ringer volume on the home screen, that's media now, so ringtones have to be adjusted in the Sound settings, in Ringer & Notification sound and then the Ascending Ringer went the way of the Dodo too.
Probably removed due to people missing the first 5 seconds or so of the call if at low volume, or missing the call entirely.
You will have to use a 3rd party app, or replacement dialler for that now.
