Unwanted space between menu and top of pages

Using Sydney child theme, hosted on Bluehost. All software is up-to-date.

After the last WordPress update, had two problems – pages moved up under the menu and hamburger menu on mobile didn’t work.

I added a line to header.php which fixed the hamburger problem, and on mobile devices the page top is now properly just below the menu.

However, for laptops there is a space between menu and top of all pages. I have tried a number of CSS code suggestions from forums, and nothing impacts the issue.

Suggestions?

thx, rob

The page I need help with: [log in to see the link]