thank you for response so quicky. I did, what you advised. I deactivated one after another each third-party plugin and tested, if the frontboxes appear. They did not. Then, I restored my last serverside backup. The frontboxes appear as we like it. Then, I deactivated again each third party plugin and did the update to wordpress 4.8. After that, I updated to the last vision core plugin and agama template version. After that, the frontboxes disappeared again.
Then I did all the same again, WITHOUT updating vision core plugin 1.07 and agama pro 1.3.8
Everything works fine.
conclusion: I guess, there could be a bug in vision core plugin or agama pro template. I hope, I could help you.
Visiting the website http://www.kaffeekoster.de you will see all frontboxes correctly. This is, why I did not use vision core ver. 1.07 and the latest Agama pro version 1.3.8
regards