User can't edit articles even if has got permissions

Hello to everybody,
I've been creating a "editor" user in Contao 3.0.6. To do so I created the user and a user group and allowed the group to edit articles, news and whatever. I then associated the user to that user group and tried all the options: keep group permissionss and extend them: in both cases the user was NOT able to edit the articles. Could see them, but not edit them.

I've been enabling all the fields required, couldn't do anything except making the user an administrator in order to let him edit posts (which is obviously EVIL).

Did you ever experience anything like this?

Thank you in advance

did you try to alter the settings in the site structure section, "permission rights"? Make this part active. I think this should be enough. If you choose the group you've made in the dropdown "group". See if the right are sufficient