functions.php

function wc_conver_special_chars_bookings( $data ) {
    if ( isset( $data['summary'] ) ) {
      $data['summary'] = htmlspecialchars_decode( $data['summary'] );
    }
    
    if ( isset( $data['description'] ) ) {
      $data['description'] = htmlspecialchars_decode( $data['description'] );
    }
    
    return $data;
}
add_filter( 'woocommerce_bookings_gcalendar_sync', 'wc_conver_special_chars_bookings' );