Hi,
We are not sure why that is happening. We would like some more information.
1. Can you confirm you are a site admin? If you are not sure go to Users->Your Name and see what role you have.
2.Can you confirm you are using the most recent Yoast SEO v5.8? If not and you updated does the issue resolve? This guides explain more about how to update: https://kb.yoast.com/kb/how-can-i-update-my-free-plugin/.
3. Can you confirm you are using WordPress 4.9? 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/.
4.Can you take a screenshot of what the Yoast dashboard looks like? To then share it to the forum you can use an image sharing tool like https://pasteboard.co/.