mending,
Sorry to hear you’re having trouble here, but hopefully I can help. While we can’t provide direct support the Yoast plugin, you can customize the titles that are displaying on specific events pages by pasting the following snippet into your theme’s functions.php file and customizing to fit your needs: https://gist.github.com/ckpicker/cef90cffb87a99eaab5f
Note the comment at the top of that snippet. Since you’re using Yoast, you’ll want to be using the ‘wpseo_title’ filter to customize your page titles. Give that a shot and let me know if it does the trick. Thanks! 🙂
-Casey-