If I understand correctly you essentially want to display Posts of the same category as the one that is currently being viewed. If so then you can do this with a view.
Go to Toolset -> Views and create a new view for that same post type and then add a query filter to that view for the specific taxonomy and then set the filter to get the value from the current page that the view is on.
Then just populate the view with the loop wizard with the additional info that you want that view to display. From there you can simply add your view to your elementor template.
before moving on pls let me understand the category function,... I only created categories for the standard posts,... not for the category of the cpt. Is it right to do so?
because i created a filter as you described, but the result ist that it seeems to be no filter, all posts were shown.
Based on what i'm seeing the correct information is being displayed.
If you take a look at the page you will see that i've output the taxonomy values for each post and they seem to be matching the page that its on. versteckter Link
Thanks,
Shane