Matching boxes overlapping Feedback in Knowledge Check Issue

Just reposition your feedback boxes so that they are not underneath the selection boxes.  There appears to be plenty of room on the slide.

I don't think this is a Fluid Boxes project, because the quizzing master slides in such a project combine all the feedback messages in a static fluid box, which is clearly separated from the answer area. Anyway can you confirm this guess?

You see the feedback messages in the quizzing master slide for the Matching question. Can you post a screenshot of that master slide?  Which theme do you use?  Was the theme updated to the present version you are using, if you use a custom theme?  

Last question; if the screenshot shows a real quiz slide, you have been deleting a lot of embedded objects. Those are the objects without an individual timeline. Quiz slides can behave in a weird way if you do delete those objects. Some of them can be deactivate using a check box, but some not. Did you delete embedded objects on the quiz slide?

Is this a responsive design project? If so, it can be challenging to align your variable placeholder objects for question slides. My solution would be to edit the position and layout of the matching slide on your master slide or consider using drag and drop as an alternative.