Access a property of an incomplete object after security release SA-CORE-2019-003

We are using Globallink for a while and it works perfectly. Since the security release SA-CORE-2019-003 (https://www.drupal.org/node/3034490) the due date object stored in settings is no longer able to be unserialized correctly and submitting a job throws the exception

Drupal\globallink\Plugin\tmgmt\Translator\GlobalLinkTranslator::requestJobItemsTranslation(): The script tried to execute a method or access a property of an incomplete object. Please ensure that the class definition "Drupal\Core\Datetime\DrupalDateTime" of the object you are trying to operate on was loaded _before_ unserialize() gets called or provide an autoloader to load the class definition ...