Dropdown menu on sticky header hidden below hero image

Hi. I have a dropdown menu within a menu on a sticky header. When the dropdown is triggered it appears below the hero image row. I have tried using the z-index css property but still can’t get it to sit above the hero image.
Any ideas how to fix this?
You can see it here:

I fixed it. The row was set to have it’s content ‘clipped’. I found it under row settings.