I think you can experience such kind of a problem, because provided page is very huge. I countend 10 Pricing Tables on it, two popups and a lot of other content there. Also, this page has some JS errors in browser console: http://prntscr.com/k5693v, which also can slow down it’s loading.
There is can be a conflict with your other plugins or your theme. We hope you understand that we can’t test our products with all other plugins and themes that are available on the market, and we can’t control the other developers. Therefore bad code of other plugins or templates can provoke a lot of problems.
Please try to deactivate all your plugins one by one and check the issue. Thus you will find out which plugin causes the error. If it won’t help, try to switch temporarily to a standard WordPress theme.
More useful information you can find here: https://supsystic.com/tips-for-solving-issues-faster/
Afterwards let us know about the result. This will help our developers to solve your problem faster.”