Vertical Spacing Issue between vocal staff and grand staff

I have a basic PVG layout with a braced grand staff and a single vocal staff above. I cannot seem to find a vertical spacing option in the layout options that adjusts the vertical spacing between the vocal staff and the grand staff. My assumption was that braced staff to unbraced staff would be the go-to, but no change occurs no matter what values I plug into the various vertical spacing fields. Which vertical spacing option do I need to adjust here, and and if the layout is not responding, why might that be?

Try “Staff to staff group”.