This should no longer occur when you are using the most recent version of Yoast SEO. This used to be a feature called clean slugs which automatically removed stop words from the generated slug. It has always been bug prone and is not really important for SEO anymore, so we removed it in Yoast SEO 7.0.
If you are using an older version, please update to the current 12.7.1 version.
If you are using the current 12.7.1 version, something else on your site is causing the unwanted behavior. The fastest way to find out what causes the behavior is to?deactivate all 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.
