I wanted to modify the header to add a third column to the top bar to contain search. That was easy as was setting the styles for the layout rather than the preset styles. However, the sticky menu would not work. The predefined layouts were all corrupted by the changes I had made. Very strange. I could not revert to an original layout and get the sticky menu to work again. My alternative was to rename the template and reload the orginal Helix layout and use the predefined header. Sticky menu works then.
It's not a critical problem, but I hope you enable people to change the layout without corrupting the header code.