Nav Disappears on archive pages

my main navigation and footer navigation both disappear on archive pages only

If I do:

<?php if(is_archive())
wp_nav_menu();
?>

I get a all top level pages, and if I try

<?php if(is_archive())
wp_nav_menu( array( 'theme_location' => 'main_nav' ) );
?>

I get nothing, and if I register a new theme location and nav and try calling that in the array I also get nothing.

I’m using wordpress-bootstrap

Any idea’s at all would be appreciated.