Graphviz only showing single edge to node even with multiple edges

I'm having trouble with getting graphviz_draw to display the same edges as
graph_draw. graph_draw displays the correct number of edges. (Please ignore
the color differences. I'm not concerned with that just now)

Using the same graph the following calls generate graphs with different
topologies:

graph_draw(g, vertex_text=g.vp.label, output_size=(500,500))

<http://main-discussion-list-for-the-graph-tool-project.982480.n3.nabble.com/file/t496149/graph1.png&gt;

graphviz_draw(g,
                    #vsize=.00001,
                    size=(1000,1000),
                    ratio="auto",
                    layout="dot",
                    splines=True,
                    penwidth=1,
                    vcolor=g.vp.x_in,
                    ecolor=g.ep.score,
                    vprops={"label": g.vp.label},
                    vcmap=cm.OrRd,
                    ecmap=cm.OrRd,
                    eprops={
                            "arrowhead": "normal",
                            "arrowsize" : 2.0,
                           },
                    gprops={"label" : g.gp.x_in,
                            },
                    overlap="prism",
                    output='network.png')

<http://main-discussion-list-for-the-graph-tool-project.982480.n3.nabble.com/file/t496149/graph2.png&gt;

All filters have been cleared prior to calling these functions. Any ideas
what I'm doing wrong? I'm fairly new to using graph-tool and graphviz.

Please take a look at graphviz' extensive documentation:
https://graphviz.org/documentation/

It's been a long time I don't use graphviz myself, so I don't remember how
to control the placement of parallel edges.