Unknown Object in Custom Static Datasource

Hi,

I created a custom Maniphest multi-value field wherein I’m using a static map as datasource. I was able to properly save and load the values from storage. However, when I’m going to update the field it shows Unknown Object (???), see screenshot below.

Datasource

public function buildResults()
    {
        $results = array();
        $bugTypes = [
          'functionality' => 'Functionality',
          'ui' => 'UI',
          'bad_ux' => 'Bad UX',
          'browser_compatibility' => 'Browser Compatibility',
          'localization' => 'Localization',
          'error_handling' => 'Error Handling',
          'performance' => 'Performance'
        ];

        foreach ($bugTypes as $key => $value) {
            $result = id(new PhabricatorTypeaheadResult())
            ->setName($value)
            ->setPHID($key)
            ->setIcon('fa-bug');
            $results[] = $result;
        }
        return $results;
    }

ManiphestCustomField

public function renderEditControl(array $handles)
    {
        $value = $this->getFieldValue();
        $control = id(new AphrontFormTokenizerControl())
        ->setUser($this->getViewer())
        ->setLabel($this->getFieldName())
        ->setName($this->getFieldKey())
        ->setDatasource($this->getDatasource())
        ->setValue(nonempty($value, array()));

        return $control;
    }