You've got a number of plugins active on the site right now and from what others have said deactivating everything fixes the issue.
A few things to try are first, re-download the theme files from themeforest (today). Re-install all of the theme files once again in case something was corrupted or not fully overwritten.
Deactivate all plugins and dropins except WooCommerce and refresh the live site 3-4 times while not logged in just to make sure you aren't viewing anything cached.
So far every time someone has had an issue with the product tabs it has been a plugin. On my live install with just Wordpress, Replete and WooCommerce I've got a few bugs that have already been reported but the tabs are working fine.