Content of hidden page not shown in workspace preview
New pages in a workspace are created as hidden per default. If either the hidden page or enabled version (the new-placeholder still stays hidden) shall be previewed in the frontend, no content elements are shown.
Parts of previous TYPO3 CMS 7 behavior of PageRepository has been extracted to distinct query restriction interceptors. However, back then not any enable restrictions were not applied if workspaces version preview was active.