HoloViews Area Overlay Axes and Labels

Question

I'm trying to overlay Scatter and Area , but the latter is causing the axes and their labels to disappear.

import pandas as pd
import holoviews as hv
hv.extension('bokeh')
from bokeh.models import HoverTool

data = dict(A=["A1", "A1", "A1", "A1"], B=["B1", "B1", "B1", "B2"], C=[10, -5, 23, 9], D=[0, 5, -7, 6])
df = pd.DataFrame(data=data)

df_hv = hv.Dataset(df)

hover = HoverTool(
    tooltips=[("C", "@C{0,.0}"),
              ("D", "@D{0,.0}")]
)

scatter = df_hv.to(hv.Scatter, kdims=["C", "D"], vdims=["C", "D"], groupby=["A", "B"]).redim.label(x="A (unitA)", y="B (unitB)")
area =  hv.Area([(0, 0), (10, 9), (30, 8), (25, -11), (15, -12), (0, 0)]).opts(style=dict(color="lightgrey", line_color="white", line_dash=None, alpha=0.5)).redim.label(x="A (unitA)", y="B (unitB)")

And then:

%%opts Scatter [tools=[hover]] (size=10)
scatter * area

The result is as follows:

If you replace the hv.Area line with the following,

area =  hv.Curve([(0, 0), (10, 90), (30, 80), (25, 110), (15, 120)]).opts(style=dict(line_color="black", line_dash="dashed", alpha=0.5))

you'll see the axes and their labels:

Is this a bug? Or am I missing something?

bokeh=0.12.7
holoviews=1.8.3
pandas=0.20.2
python=3.6.1

UPDATE

After one of the comments, I changed the area as follows,

area =  hv.Area([(0, 0), (10, 9), (30, 8), (25, -11), (15, -12), (0, 0)]).opts(style=dict(color="lightgrey", line_color="white", line_dash="solid", alpha=0.5)).redim.label(x="A (unitA)", y="B (unitB)")

But that has an ugly line along the origin as a side-effect:

And it doesn't get better if I do line_color="lightgrey" .

UPDATE 2

Adding the option line_alpha=0 solved the issue as recommended in one of the comments.

area =  hv.Area([(0, 0), (10, 9), (30, 8), (25, -11), (15, -12), (0, 0)]).opts(style=dict(color="lightgrey", line_color="white", line_dash="solid", alpha=0.5, line_alpha=0)).redim.label(x="A (unitA)", y="B (unitB)")

Answer 1

I'm not quite sure how or why this is occurring (I suspect it's something in BokehJS), but it seems to be the line_dash=None in style options for the Area element, if you remove it or replace it with line_dash='solid' the axes return.

I'll follow up and will probably file an issue in bokeh.