Hi,
It seems to be a template issue, if bet that if you try with the default Joomla template you don't have this issue.
That looks like a z-index matter, the menus are potentially using a z-index grater than the one used by the popup.
So please add/edit css properties to change the z-index values.
Here is some documentation for that:
www.hikashop.com/support/support/documen...ize-the-display.html
Another solution can be to select another value for the "Address selector" option in Configuration > Checkout > Login & Address