Hi Tammy,
It sounds like the desktop header is being replaced correctly by your Conditional Header, but the theme is still loading the mobile navigation from the Main Menu.
Check the header settings for the mobile breakpoint and make sure the Main Menu element is disabled/removed for mobile devices. In many themes, the mobile menu is configured separately from the desktop menu, so hiding the desktop Main Menu alone will not prevent the mobile version from appearing.
If your theme doesn’t provide a mobile visibility option, you can hide the Main Menu on mobile with custom CSS by targeting the mobile navigation container and setting it to display: none; for smaller screen sizes.
Could you let us know which theme or header builder you’re using (Astra, Elementor, Kadence, etc.)? That would help provide the exact steps. ☺️
