For any page loading issues, we recommend turning off AJAX page transitions. Page transitions create nice effects when navigating through a website. When transitions are turned on, the header and footer are not reloaded. Only the content gets reloaded. This can cause loading issues, usually with third party plugins, because they require their scripts to be loaded in the header or footer and they are not. 

Depending on your theme, page transitions can be turned off from one of these locations:

Theme Options > General > Settings > Page transition (put No animation)
Theme Options > General > Settings > Smooth Page Transitions (put No)