I'm trying to use two numerical attributes for two different styles for the symbology of my map, one for color (types) and one for size with manual classes. When selecting these two attributes, smart mapping only gives one option for the drawing style: Types and size. Okay, sounds about right, so I choose it. Now my problem is that when I go to the options for the size attribute, it doesn't have the option to classify the data. It isn't even grayed out, it's simply not there (see attachments, sorry about the Finnish language version but the 'classify data' option is shown as 'luokittele aineisto' on the size options). As you can see from the screen captures, I've tried it with just one attribute using the counts and amounts (size) drawing style, and with the very same data, the size menu let's me classify the data, so it's not a problem with the data I'm using.
Is the classify data option for the size attribute missing by design when using the Type and size drawing style, or is there some kind of a bug here?