Popup not centered on production site

Hey there, need help with the popup on http://lawyersclubchi.wpengine.com/ it's not loading in the center of the screen if accessed for the first time, but if the user accesses a second time or refresh the page then it appears in the center of the screen.

But in the staging version, it works from the beginning http://lawyersclubchi.staging.wpengine.com/

Support access is enabled on both sites, the popup shows after 2 seconds on homepage.

Thanks in advance!