I have DatatypeProperties / Attributes in my data - I see them in query builder:
And when I use them to query the data, I get a result. But then I don't see the actual attribute in the result visualization: Screenshot by Lightshot (I only see the object properties here).
I also don't see any attributes in the general visualization of the graph (i.e. with no query active, just plain viewing the graph) - only object properties: Screenshot by Lightshot
Yes, this is intended. Attributes are not shown in the visualization for Explorer. The attribute values for each class instance can be viewed by right-clicking the instance and selecting See details. A details panel will open, showing all properties (objectProperties/relationship and datatypeProperties/attributes) for that instance.
This details panel can also be opened from the list view by clicking on any list result.