I can give you ours if this is still an open issue. Our conflict seems to be that both Yoast and WPForo are creating meta descriptions, so we have two and it is causing a problem with search engines.

Should I start a new thread?  

Just drop YOAST bloatware (to be kind to Yoast) and use SEO Framework.

Light as a feather and works great with wpForo.

https://wordpress.org/plugins/autodescription/

Posted by: GreenAppleMD

I can give you ours if this is still an open issue. Our conflict seems to be that both Yoast and WPForo are creating meta descriptions, so we have two and it is causing a problem with search engines.

Should I start a new thread?  

As you can see here wpForo disables 90% of Yoast meta tags in header and adds own data. We use Yoast here.Try to change the theme, sometimes themes make this conflict with Yoast and wpForo. Because they don't conflict in 99% cases. The SEO Framework plugin is also great in case your conflict is not fixed.

Do you still use Yoast?

Mark