We'll create fresh WordPress site with Flush Opcache with Varnish installed. You have 20 minutes to test the plugin after that site we'll be deleted.
Flush Opcache with Varnish automatically flushes the PHP Opcache when one of the “Empty Cache” buttons that Mika Epstein’s excellent Varnish HTTP Cache creates are clicked.
If the WP Opcache plugin is installed it is used to flush the opcache to let the opcache be re-warmed according to your WP Opcache settings, (and you can turn off WP Opcache’s “Flush PHP Opcache” button from the Admin toolbar).
If WP Super Cache is installed then the WP Super Cache cache will be cleared as well.
Please request support in this plugin’s support forum on wordpress.org. This way there is a public record of solutions that work for people.
Please submit issues and Pull Requests to the Github repository.