V2.2.8 breaks Twenty Seventeen design

After automatic upgrade of the free version to v2.28 I notice a change of the static start page of my site http://www.biker-reise.de
The update breaks the design of the start page. I use some random header media pictures an the option to show latest blog postings with an own picture in the second section of the start page.

Normal the start show a picture full size, menu at the bottom. If you scroll down you should see the second picture full size followed by the blog section. After the update 2.28 the first header picture is minimized to banner size (as it used on all other pages) and the second section picture shows up in midsize (?). The text is limited to the width of the second picture.

If you need screenshots please ask and I will do some for you.

Regards
Andreas