top menu bar jumps when scrolling

There is an intermittent problem when scrolling on the main page that only happens when there is a header image.

When scrolling down the page, the top menu bar jumps to the top to the screen and stays there. Sometimes it scrolls smoothly before sticking.

After some googling, I see that this is a problem in the javascript doing the calculations of where the menu should go without checking if the header image has been loaded. I’m overwriting the javascript in my child theme to do the fix, but I’d rather not be overwriting functions.js in my child theme long term. Is there any plans to patch this in the official theme?

The javascript fix is to change line 63 from this:
$( function() {
to this:
_window.load( function() {

You can see the bug (intermittently) here:
https://www.asdesigned.com/test2/

Thanks