As you can see, emulaton mode is turned off in connector
So, in order to use multiple named placeholders with same name, you have to override this option in app/config/database.php, adding options
parameter like this
'mysql' => array(
'driver' => 'mysql',
'host' => 'localhost',
'database' => 'database',
'username' => 'root',
'password' => '',
'charset' => 'utf8',
'collation' => 'utf8_unicode_ci',
'prefix' => '',
'options' => array(
PDO::ATTR_EMULATE_PREPARES => TRUE,
),