Seems like this has changed in the newest typo3 version, so I created a static function in my DebugService:
public static function debugQuery($query){
$objectManager = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance('TYPO3\\CMS\\Extbase\\Object\\ObjectManager');
$queryParser = $objectManager->get(\TYPO3\CMS\Extbase\Persistence\Generic\Storage\Typo3DbQueryParser::class);
\TYPO3\CMS\Extbase\Utility\DebuggerUtility::var_dump($queryParser->convertQueryToDoctrineQueryBuilder($query)->getSQL());
\TYPO3\CMS\Extbase\Utility\DebuggerUtility::var_dump($queryParser->convertQueryToDoctrineQueryBuilder($query)->getParameters());
}