Unable to resize height dimensions of quiz answer options box

The same happens to me - is there a way to fix it? I am customizing Master Layouts and came across the same problem that is described here: When I insert a question slide and try to change the height of the Answer Box it gets really tiny and a scrollbar appears. If I change the master layout it turns back to normal size, but as soon as I change the height of the Answer Box it happens again.  

I read that someone had it fixed by importing the slides in a new project but that didn't work for me. Are there any other solutions?

Update: In my original .story I modernized the project text (my storyline is in German - I don't know the wording in English, sorry). In the new .story-file where I imported the slides I left the project text as it is. When I changed the settings so that the text box gets smaller to fit the size of the Text, I'm suddenly able to resize the Answer Box. I don't understand why the same setting didn't work for the modernized text, but it seems to solve my problem for now.