Unknown column 'a.unregistra_until' in 'field list'

When an event has been created in backend it will be listed in the event list for the user correctly.
But when the user, who is not logged-in and is no admin, tries to open the event following error appears on screen: "Unknown column '' in 'field list'"
See attached screenshots.
Kind regards
Thomas

Hi, my apologies: I was in holidays
Does your problem persists? Because, looking into your site, I don't see any problems.
If yes, please give more details about your Joomla and JEM versions....

Hello,
yes, the issue appears again. Also if you try to click on an event on the startpage the same error happens.
Example: :allerheiligenmesse
Joomla version: Joomla! 4.3.3 Stable [ Bora ] 11-July-2023 16:00 GMT
JEM version: 4.0.0
PHP-Version: 8.0.28
Kind regards
Thomas

is this in your livesite?
I was looking there, but I see events in frontend.
Strange is: there is no link to the event details view!

Yes, it is our livesite.
Try to click on "read more" (see screenshot).

I am not admin and I am not logged in, then I see only: