on my website, only admins should be able to write articles. This should be easily done by adding and removing the "add article" permissions in the use roles. 

However, it has no effect and every user can write articles, even if the user role says they should not be able. Even if I remove the possiblity to add articles by admins, every admin can still write articles. 

As you can see (screenshot attached) the user roles have no influence on the permissions of writing an article. 

Please fix.