problem Replacing Excerpt ‘ ‘ by ‘…’

Hello,

On the Envince theme, there’s no Excerpt, or more specifically, it doesn’t display anything. Upon investigating, I noticed that in the file: inc\theme.php, there’s a section supposed to remove the ‘…’:

if ( ! function_exists( 'envince_trim_excerpt' ) ) :
  function envince_trim_excerpt($text) { 
  return ''; 
} 
endif; 

add_filter('excerpt_more', 'envince_trim_excerpt');

However, changing this: return ''; to this: return '...'; doesn’t change anything.
I’ve tried many other things without success:

function envince_trim_excerpt($text) {
  return $text . '...';
}

I even doubted this function and deleted it to see, but it doesn’t change anything (cache consistently cleared).

if ( ! function_exists( 'envince_excerpt_length' ) ) :
/**
 * Adds a custom excerpt length.
 *
 * @since  1.0.0
 * @access public
 * @param  int     $length
 * @return int
 */
function envince_excerpt_length( $length ) {
	return 70;
}
endif;

This one works perfectly fine.

What should I do to add those unfortunate three dots? Or perhaps display a “Read More” link instead? Best regards,