Elements: Need nav menu to be on top of page content

Hi Tom.

I was using the old Page Headers on a site which I have just migrated from a multisite to a single site. The old page headers were lost during migration and so I am trying to set everything back up with elements. However, no matter what I try I am losing my primary nav menu which is disappearing behind my page content.

Please see the two website url links which I have privately added. The first is the old subsite before migration with page headers, the second is the single site after migration with elements.

Any idea what I am doing wrong here?

Thank you.