HTTP 500 error

The 500 Internal Server Error is not likely related to the caching issues but sometimes the issue may be fixed after you clear the browser cache & cookies.

If still this error comes then check Error Log.
Or it could be memory-related. In this case, follow the simple step:
Go to WordPress Dashboard>>Divi>>Support Center and check the System Status.

Another reason for this error could be limited memory and other resources available to your website causing the website to generate this error once in a while. If you are using plugin like Divi Plus, try disabling the module that you don’t want to use to optimize memory usage.