Hi there,
The One Page Navigation functionality is not completely available in Pro yet. It was not available at all in the previous version, but in the new version which you installed already the smooth scrolling functionality is working, but the code does not calculate the sticky header height at the moment.
There are many factors involving the height of the sticky header due to the complex nature of the Header Builder.
Our development team is working to introduce an alternative for this, but at the moment be informed that the One Page Navigation functionality is not ready for Pro.
Thank you for your understanding.