WordPress YOAST -- Add Trailing slash to canonicals on homepage only. Add to functions.php file of theme.
//** Fix Canonicals **//
function wpseo_canonical_home_url_fix( $canonical_url ) {
if ( is_home() ) {
return trailingslashit( $canonical_url );
} else {
return $canonical_url;
}
}
add_filter( 'wpseo_canonical', 'wpseo_canonical_home_url_fix' );