At fr.wiki [[ https://fr.wikipedia.org/w/index.php?title=Utilisateur%3AElitre_%28WMF%29%2FProve_VE&diff=113097710&oldid=113097648 | I tested Citoid ]] and gave it the link to a user sandbox.
I get a "{{Article}} : paramètre « périodique » manquant" error. When I click on Modifier, I'd expect the field for the required parameter to show up immediately in the inspector, rather than having to look for it.
If I try this on test2 (same URL) I don't get the same error, so it must be related to TemplateData.
This is due to the fact that these url is coming back as itemType blogPost, but being cast to Article, which does not have a way to translate the field "blogTitle" to "periodique". This is a very general problem having to do with the way we translate between our types and templateData types, and unfortunately is not easily resolvable.