TYPO3 Core

In TYPO3 9.5.6 is a preview record function implemented that expects some kind of version information for workspaces support:

typo3_src-9.5.6/typo3/sysext/backend/Classes/Controller/EditDocumentController.php

1031:
// Always use live workspace record uid for the preview
if ($GLOBALS['TCA'][$table]['ctrl']['versioningWS'] ?? false && $recordArray['t3ver_oid'] > 0) {
$recordId = $recordArray['t3ver_oid'];
}

We get an empty preview because the uid for the record is 0 even if t3ver_oid is 0.

https://www.mydomain.de/aktuelles/news-ansicht?tx_news_pi1%5Baction%5D=detail&tx_news_pi1%5Bcontroller%5D=News&tx_news_pi1%5Bnews_preview%5D=0&cHash=13e1c8c16a8cc08512a8e5b39a425984

When you disable the versioning feature in the TCA from your extension it works.