Fix 504 Gateway Timeout / 500 Internal Error

After updating the Divi Theme on a website, we've been experiencing a 504 Gateway Timeout / 500 Internal Error on our blog posts. Every other page is loading fine. This is not an intermittent issue, and it either shows the 504 or 500 error. It's happening while trying to edit a post in the WordPress dashboard and when loading the page on the front-end. We're hosting with Siteground and so far they have stated, "for 92 executions, your account used up about 1200 seconds. This means some executions take more than 12 seconds to finish" So far, our attempts at fixing the issue have been disabling the WordFence plugin (thinking it was a firewall issue). We've disabled all plugins and found the issues persisted. We've also further optimized the site and added the following dynamic timeout code to the htaccess file: <IfModule mod_dtimeout.c> <Files ~ ".php"> SetEnvIf Request_URI "[login to view URL]" DynamicTimeout=300 SetEnvIf Request_URI "wp-admin/[login to view URL]" DynamicTimeout=300 SetEnvIf Request_URI "wp-admin/[login to view URL]" DynamicTimeout=300 SetEnvIf Request_URI "wp-admin/[login to view URL]" DynamicTimeout=300 </Files> </IfModule> Please let me know if there is any additional information required. Thank you kindly!! :)