@boue We’re sorry to hear you are experiencing this issue on your site.
We checked on the page in both Google’s Structured Data Test Tool here, and also the Schema.Org validator here, and whereas no errors or warnings were detected in Google’s tool, we do see the error you reported when testing the URL in the Schema.Org validator.
Can you please confirm you are using the most recent release of Yoast SEO version 18.8? You can learn more about updating here: https://yoast.com/help/how-can-i-update-my-free-plugin/
Also, can you confirm you are using WordPress 5.9.3? You can check by clicking on the W in the top left and selecting About. If you need to update, please check with your host provider. Please know that if you are using an older version of WordPress Core you may experience unexpected behavior with Yoast. This guide explains more: https://yoast.com/why-we-dont-support-old-wordpress-versions/
If you update to the most current version of WordPress and Yoast SEO, does this resolve the issue?
If you have confirmed both WordPress, Yoast SEO, and all of your site’s other plugins and themes are up to date and the problem is still occurring, we would next recommend performing a conflict check. A plugin or theme conflict can sometimes cause functionality problems, errors, or unexpected behavior from the plugin. If you are unfamiliar with checking for conflicts, we have a step by step guide on how to check for conflicts available here: How to check for plugin conflicts.
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.
Can you please confirm you have performed a complete conflict check by disabling other plugins, and resetting the theme to a default such as TwentyTwentyOne and let us know the results?
If you do not feel comfortable to do this yourself or if this does not solve your issue, our Yoast SEO Premium plugin comes with one year of (technical) support.
