[Peter van Cooten]

Thank you. Fortunately I have made the modifications in a child theme.

[Peter van Cooten]

Fixed it with CSS. (Unfortunately it seems I cannot remove my original question)

[Peter van Cooten]

I now see a menu, but clicking it opens a search box, not the menu..

[Peter van Cooten]

For those interested: I solved the problem with this CSS:

#header-image-main-inside {
  display: -webkit-flex; /* Safari */
  -webkit-align-items: center; /* Safari 7.0+ */
  display: flex;
  align-items: center;
}

Website: www.ambientblog.net/blog/stg_31b9b

[Author]

Posts