Hey @mediaconsulting_com,
The issues you described most probably was caused by caching. Please check for the following first:
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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.
 
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Clear all caches including browser cache then deactivate your caching plugins and other optimization plugins.
 
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If you’re using a CDN, please clear the CDN’s cache and disable optimization services.
 
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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.
 
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Remove custom CSS, Javascript and templates.
 
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Reset your htaccess file by renaming it to .htaccess-bak. Then in WP Admin Menu, go to Settings > Permalinks and just click the Save Changes button.
 
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Slow back-end mostly is caused by low memory setting. 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' );
Thanks.