Sticky Haeder, Anchor – Spring point set -x

This is a limitation of your browser or site design. The A-Z Listing plugin uses anchors within the document which are a native thing implemented by your browser. There is no code to “move” the page other than a simple <a href="#letter-x">X</a>. If you want to customise the behaviour you will need to do so according to however you do it for other inside-the-current-page links. This probably means using a DOM Event Handler to hook into the click event and prevent the default action followed by moving the page to your desired position programmatically.

Stack overflow has an example (first valid result from a Google Query, so there may be more methods or better methods) https://stackoverflow.com/questions/1586341/how-can-i-scroll-to-a-specific-location-on-the-page-using-jquery