[Tony]

Brilliant! The first worked.

My test site is now back on Attitude (actually via my Attitude Child theme). The search field is on a line above the button and also the Order By: is on a line above the select box. This uses unnecessary vertical space. With the Twenty Sixteen theme the search field appears on the same line as the search button and the Order by: label on the same line and before the select box. I think Attitude should follow this arrangement.

If you feel this is beyond your support duty, could you give me some pointers what to do or where to look?

thank you for your excellent help.