@benedictadam We’re sorry to hear you are experiencing this issue on your site.
If you have confirmed that you have configured a meta description for the post but are not seeing one output in the post’s source code, we would first recommend to clear your cache. If you clear your cache (server, plugin/theme, browser, or CDN such as Cloudflare) does this resolve the issue?
If you are not sure how to clear your server cache you should speak with your host provider. We have information on how to clear your browser cache at the following link: https://yoast.com/help/how-to-clear-my-browsers-cache/
If the issue still occurs after clearing your cache, we would next recommend performing a conflict check. This will help us narrow down the exact cause and determine what the next steps are while saving you time.
Just to be sure, we would like to rule out any plugin or theme conflicts that may occur. The fastest way to do this is to?deactivate all non-Yoast plugins and switch to a standard theme?like?Twenty Nineteen.?
Test this on your development or staging site, if you have one. If not, we recommend using the?Health Check & Troubleshooting?plugin. This plugin allows you to run a conflict check?without affecting normal visitors to your site.
If you’re unfamiliar with checking for conflicts, we’d like to point you to a step-by-step guide that will walk you through the process:?How to check for plugin conflicts.