This typically happens when something on your site (most likely your theme) uses the wrong title call – wp_title (entire page title) vs the_title (post only title).
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.
As we can imagine that 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.
Once you determine what plugin or theme is using the wrong title call, please contact the author or support team for the plugin/theme for further assistance.
This thread has been marked as resolved due to a lack of activity.
You’re always welcome to re-open this topic. Please read this post before opening a new request.
Thanks for understanding!