Suppress flexslider on posts page for Sparkling WordPress theme

@oneillg You can try achieving this by using the attached modified plugin that contains following code but please note if the user accesses post URL directly in the browser then the user can access the post.

function exclude_category( $query ) {
	if( of_get_option( 'sparkling_slider_checkbox' ) == 1 && !is_admin() && $query->is_main_query() ){
		$slidecat = of_get_option( 'sparkling_slide_categories' );
	        $query->set( 'cat', '-'.$slidecat );
	}
}
add_action( 'pre_get_posts', 'exclude_category' );

You can also use pages for the slider instead of posts by using the solution posted in the following topic.

https://colorlibsupport.com/t/slider-for-pages/#post-33351