Header lists posts instead of showing primary nav menu

Question

I recently began experimenting with WordPress Multisite and I'm running into an issue with the primary navigation menu. Instead of showing the items in the menu that's registered as the primary menu, it just lists around 20 pages.

I'm using the same theme as the master site on the network and I've copied some of the tables (posts, terms, and most options) from the master site. The tables were copied directly in MySQL and not through a plugin.

This is the code I'm using in the header to insert the main nav menu and it works on the master site:

<?php wp_nav_menu( array(
    'theme_location' => 'main_nav_primary',
    'container'      => false,
    'menu_class'     => 'main-nav__primary__list loading'
) ); ?>

The menu is registered in functions.php, and I've added the menu as the primary menu in the theme locations.

I looked in my options table for relevant options and listed them below. There may be more options I didn't find with my query.

+-----------+-------------------------------+-------------------------------------+----------+
| option_id | option_name                   | option_value                        | autoload |
+-----------+-------------------------------+-------------------------------------+----------+
|       103 | widget_nav_menu               | a:1:{s:12:"_multiwidget";i:1;}      | yes      |
|       485 | nav_menu_options              | a:2:{i:0;b:0;s:8:"auto_add";a:0:{}} | yes      |
|      4016 | wp-optimize-enable-admin-menu | false                               | no       |
+-----------+-------------------------------+-------------------------------------+----------+

Do multisite menus have to be configured differently? I've set up my network to use sub-domains, also.

Answer 1

Thanks to help from @Milo, I was able to figure it out. It had to do with the 'theme_location' => 'main_nav_primary' line in the wp_nav_menu function call in the header. In functions.php, the primary menu was just registered as primary so I had to change the function call to 'theme_location' => 'primary'.

I find it odd that the master site still served the correct menu with this discrepancy, but I'm going to assume there is some option or filter that made that happen and try to figure out which.