I'm using the new ArcGIS Online Map viewer to create a series of web maps. The point data in the maps is symbolized by Type (unique values) on a field from the hosted feature layer. Under the Style options, I notice it is no longer possible to change the symbol size for each unique point symbol (screenshot 1).

It seems like it's missing. This was possible in Map Viewer (Classic) (screenshot 2).

I'm wondering if this is user error, or if this is a functionality limitation.