Category title output before opening title tag

Question

I am using this code to add the category title to the category archive titles:

function filter_events_title( $title ) {
  // Single venues
  if ( tribe_is_venue() ) {
    $title = sprintf('%1$s Running Race Calendar', get_the_title() );
  }
  // Category pages
  elseif ( tribe_is_upcoming() && is_tax() ) {
    $title = sprintf('%1$s Race Calendar', single_cat_title() );
  }
   
  return $title;
}
add_filter( 'tribe_events_title_tag', 'filter_events_title' );

While the category title is being output, it is BEFORE the opening tag. How can this be fixed so it is within the tags? Here's the source code:

5K  <title> Race Calendar &#8211; Running World</title>

Answer 1

You can fix that by setting the second parameter for single_cat_title() to false, which then returns the title instead of echoing it (before the <title> tag), like so:

$title = sprintf('%1$s Race Calendar', single_cat_title( '', false ) );