If there is no secondary enabled, and the shrinking header is enabled, the header starts to shrink immediately if the user scrolls down, even one pixel (which shrinks the header by one pixel). I believe this is the intended behaviour.
However, if the secondary menu is enabled, the shrinking starts with a delay. The user must first scroll down the amount that is equal to the height of the secondary menu. E.g. if the secondary menu is 30px high (as it is by default), the shrinking does not start until the return value of $(window).scrollTop() reaches 30.
I tested this with a clean WordPress installation with no other changes than enabling Enfold and enabling secondary menu in the header options. I strongly believe this is a bug (or rather a development oversight) in the function avia_header_size() in the avia.js.
Hi Elmo!
Thanks a lot for reporting the issue.
We have forward it to our developers, who will do take a look at it.
We appreciate been part of our community!
Cheers!
Basilis