In the Advanced Settings there is a ‘Stretch’ option will set the slider to fill 100% width of the container it’s in but this will not necessarily be 100% browser width.
I’m using the Vantage theme and this worked for me
Go to Appearance –> Theme Settings and then scroll down to the 3rd section HOME. Select Stretch — Stretch the home page slider to the width of the screen if using the full width layout.
Actually, I couldn’t figure out how to get away from full width and just stumbled on this setting.