I've recently encountered this feature and cannot figure out what it is. Are these null values or is Qlik Sense simply showing these stripes at the top because I have so many values for this particular dimension?
Thanks for your response! By "Key" do you mean legend? If so, yes. The legend does not explain what these striped segments are. It seems to me as though it creates a striped segment to basically show that there are too many colors to represent.