That is a strange issue, would you please follow this troubleshooting to check if the issue resolves.
Ensure everything is up to date according to our version compatibility list at https://theme.co/apex/forum/t/troubleshooting-version-compatibility/195. Please follow the best practices when updating your theme and plugins. See https://theme.co/apex/forum/t/setup-updating-your-themes-and-plugins/62 for more details.
Test for a plugin conflict. You can do this by deactivating all third party plugins, and seeing if the problem remains. If it's fixed, you'll know a plugin caused the problem, and you can narrow down which one by reactivating them one at a time.
Contact your host to increase your allocated memory or do it yourself by adding this code in your wp-config.php
define( 'WP_MEMORY_LIMIT', '256M' );
define( 'WP_MAX_MEMORY_LIMIT', '512M' );
Caching. If you have a caching plugin activated or any form of server side caching please disable it to test for any possible conflicts. If you have server side caching or aren't sure if you do, your host should be able to advise of this and disable it for testing purposes on your account.
Cloudflare. If you are using Cloudflare please disable this for testing purposes. Cloudflare by default enables an auto minfication function to compress the JS and CSS files of the theme. As the theme already serves minified files, re-minifying said files only causes to break the entire site.
In case the issue persists, would you mind providing us with login credentials so we can take a closer look? Please provide following information:
Set it as Secure Note
* Link to your site
* WordPress Admin username / password
* FTP credentials
All the best!