Thanks ! Here is my final code to fix the pb on 2 apostrophe, working on my side
add_filter( 'dgwt/wcas/phrase', function( $keyword ) {
if ( (strpos( $keyword, "’" ) !== false )
|| (strpos( $keyword, "‘" ) !== false )) {
$keyword = str_replace( "’", "'", str_replace( "‘", "'", $keyword ));
}
return $keyword;
}, 10 );