I’m seeing an empty menu with Chrome as well, so I don’t think it’s browser-specific. If I had to guess all your menu items are configured for your custom roles (how were they registered?), but you may not have given the custom role’s capability to the default admin?
NMR uses current_user_can($role)
(which isn’t ideal, but better than asking users to choose capabilities like edit_posts
in the NMR settings) to check whether an item can be displayed. Usually an admin can do anything any of the other roles can do, but your roles are custom and maybe they didn’t inherit the new role’s custom capabilities? I don’t know for sure, but I’m guessing that none of the menu items are being shown to the admin, hence an empty menu. The fastest way to fix that would be to check “admin” as an additional setting.
Can you also test as a particular role? Additionally, if every menu item requires a role, then non-logged in users (once/if the site becomes public) won’t see a menu either.