Page preview only updates once

Hello,

I’m having an issue where the WordPress Preview Changes feature will only show the state of the page from the first time it is pressed. For example, if I make an edit to the page and click Preview Changes, the preview page shows the edits. If I continue to make edits, the Preview Changes button will reload the preview page, but none of the new edits will be visible. The issue resolves itself if I deactivate the Header & Footer Code plugin.

Thoughts?