That means that two systems are trying to add in a meta description. The best way to find out what those are is to disable all of your plugins and revert to a default (Twenty-something) theme. Then re-enable your theme, then the plugins one-by-one and check after each one to see how many meta description tags there are on that page. You’ll soon find out what is doing that.
You already know that one is coming from Yoast, so when you find what the second one is you can check with the authors or support for that theme/plugin to see if that cam be turned off.
Hey there,
Seems like you’re facing a metadescription issue on some pages of your website. Using Yoast SEO for customization is a great approach. It might be that your page content is conflicting with the custom metadescriptions. Have you checked the HTML and the placement of the metadescriptions? Good luck!