Thanks for writing in! First of all, please go through the points below.
- Ensure everything is up to date according to our version compatibility list here. Please follow the best practices when updating your theme and plugins. Click here for more information.
- Go to X > Settings and click on the Clear Style Cache button.
- If you're using a CDN, please clear the CDN's cache and disable optimization services.
- Test for a plugin conflict. You can do this by deactivating all third-party plugins, and see 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.
- 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.
To further narrow down your issue, please install the following plugin (https://wordpress.org/plugins/wp-serverinfo/) activate it and then head over to Dashboard -> WP-Serverinfo section.
Then check the following server configurations.
PHP Version - We recommend PHP v5.6.x or higher to avoid incompatibility issues. I know you have done this step but just mentioned it.
PHP Memory Limit - We recommend PHP memory limit of 512 MiB. If you see a value below than that, please refer to our guide [here](Increase the PHP Memory Limit of your server. Click here for more detailed information and how to increase the PHP memory limit.).
PHP max script execution time - We recommend the value of 120 or higher (300). Here's how to increase that value (https://www.simplified.guide/php/increase-max-execution-time).
if you're still experiencing this issue, please provide us with your WordPress login credentials in a secure note to check your issue further.