Positioning menu button left within navbar

On the desktop version of the site using vertical menu, the menu toggle button is in the navbar box.
If tagline is not enabled, the menu button is at the far right of the box, whether social buttons are enabled or not.
But if social buttons are disabled and tagline is enabled, the menu button moves to the left, but not all the way to the left inside the box. It ends up in a big white space.
I’d like it to be all the way on the left of the box, so it balances the tagline on the right.
I’ve dug around for several hours and haven’t found any clues what sets the button position. I’m running Customizr 3.4.13 and have a child theme.
Thanks for any help. Bob