'component' is not a known element when rendering component on root page

In my app, I’m trying to render a component via <component></component> in my root page’s template. I’m getting the error above.

This error usually indicates that it’s not declared in an @ngModule, but I’m literally reusing a component that’s already existing in the app, but in a stack rather than THE root page.

I’m guessing this is because the stuff in @ngModule hasn’t been loaded yet? If so, what do I do to fix it?