div-styles are not shown in editor

Hi,
Up to now the plugin worked just fine. But now we have created some div-styles which won’t show in the editor’s visual panel, there only plain text is shown. Switching to the editor-text-panel shows that they are applied and in the front end view they are shown properly. The styles in question are in the editor-style.css as well as in the editor-style-shared.css.
I’m new to WP so excuse me, if this question is perhaps dumb.

https://www.ads-software.com/plugins/tinymce-and-tinymce-advanced-professsional-formats-and-styles/