Hello child theme css problem

Hi 

I created Hello child theme and unregister Hello style.css and Hello theme.css from theme settings. After unregister these child theme style.css not loading. 

I also tried with hook 

add_filter( 'hello_elementor_enqueue_style', '__return_false' );

add_filter( 'hello_elementor_enqueue_theme_style', '__return_false' );

In both cases my child theme style.css not loading.

Please suggest me solution.

Thank you