Vertex label not specified in DSE Graph snapshot 

If a vertex label is not specified when a graph snapshot is created, the snapshot will be empty.

The DataStax Enterprise Help Center also provides troubleshooting information.

If a vertex label is not specified for graph.snapshot().create(), then an empty snapshot will be created.

The result can be seen in Studio by looking at the count value for a snapshot:

This issue is fixed in DSE 5.0.6 and later.