I commented out that line from my child theme styles.css and turned off compression in the theme.
Doing that shows the magnifying glass search icon, but when I click that it only shows the pop up search form.
Ignore the search form in the side bar too, just exploring alternatives if getting the searchbar in the menu proves prohibitive.
Sorry for the confusion.
There are two headers in play on that page.
1. The header of the page itself with the logo and menus which is fixed and working properly.
2. The first line of the table should also be fixed and stay at the top of the page when you scroll down. That’s the part that I can’t seem to get to work properly.
I wasn’t sure if the code that causes the menu header to stick was preventing the code in the table from fixing the top row of grid.