I am new to debugging a theme problem but I think I found a glitch in “searchform.php”.
The placeholder string “Search …” does not get replaced even if it seems to be correctly translated. My german site still shows “Search …”.
The same is true if the search does not find anything. The page still shows “Sorry, but nothing matched your search terms. Please try again with some different keywords.”
The theme and the plugin are up to date.
Thank you for your supoort.
Andy Brunner