Sorry for the comment spam.
The filter doesn’t come from a plugin or a theme, it’s a filter from the class acf_field in field.php.
this line in __construct changes my String “29” into a int 618.
$this->add_filter("acf/load_value/type={$this->name}", array($this, 'load_value'), 10, 3);
Its the filter acf/load_value/type=taxonomy
why?