Thank you for the answer. But I’m sure that it is installed correctly.
I have found out that the problem does not occur when I use an old version of the theme … So actually it looks like it isn’t a CF7 issue …
Hmm … forget this question. Just after I posted this I realized that it’s a basic WP configuration. Off course.
Thank you for this respons!
I tried it already to remove the outline in css, but it didn’t work. Now I found another solution: I deactivated the lightbox plugin that they were using and replaced it with another plugin …
And the “phenomenon” has disappeared. 🙂