Hi @Suzanne,
It might be the 3rd party plugin SG Optimizer is the cause behind the issue, I would recommend you to deactivate the plugin temporarily after clearing the cache, and check if the issue resolves.
If that does not resolve the issue, I would suggest you troubleshot a few common issues to find the reason behind it.
1.Plugin Conflict
2.Child Theme Related issue
3.CSS/JS Customization
4.Disabling Cache
5.Permalink
If you discover that an issue is coming from a custom code or 3rd party plugin, kindly consult with a developer or contact the plugin author. Please note that we do not provide support for custom codes and 3rd party plugins.
A few hours ago, we have released another version 4.0.11, it has some issues fixed already. Please update your theme to that version. If you are still experiencing the same issues, please provide login credentials for your site in a secure note to examine it further. Unfortunately, the credential provided is not working and showing the error attached in the screenshot.
Thanks