I finally understand what is happening but yet I don’t have solutions to fix the issue :-/
I disabled all the other plugins on my WordPress and tried to activate them one by one just to see if one of them is really on conflict with Yoast SEO.
I found out that a plugin named “Advanced custom Fields PRO” is not compatible with the use of Yoast SEO. If this plugin is activated then I can’t use the first two tabs of my Yoast metadatabox when editing posts.
The thing is that I really need this plugin!
I hope this can help you too!
