TYPO3 Core

I noticed that when the page tree is loaded in (workspace) draft mode the folder containing records is displayed as modified (background-color: #fee4c9;) (see screenshot "Screen Shot 2018-08-08 at 10.59.49.png").

When I select the folder and then switch to the workspace view in BE to list the changes the list is empty (see screenshot "Screen Shot 2018-08-08 at 10.53.11.png").

I did a network inspect in the browser and I saw that following request has an error 500:

http://test.project.local/typo3/index.php?ajaxID=%2Fajax%2Fworkspace%2Fdispatch&ajaxToken=<someHash>

with the content

...
Uncaught TYPO3 Exception
#1393960943: Element "sys_file_reference:4971" does not exist (More information)

RuntimeException thrown in file
/home/vagrant/code/project-typo3/vendor/typo3/cms/typo3/sysext/version/Classes/Dependency/ElementEntityProcessor.php in line 186.
...

When looking up the entry in the DB the record in sys_file_reference is gone!? (see screenshot "Screen Shot 2018-08-08 at 10.57.10.png").

Is it normal that entries gets (permanently) deleted in the DB?