When trying to change data series: XAxis not defined.

I made a Windows Form for "streaming" data asynchronously from a set of running benchmarks. I create the PlotModels in advance, and whenever new data arrives, I call model.Series.Clear() and then re-add the Series again to show the new data.

The first time the data is displayed, everything works fine. But after clearing and re-adding the series (without changing the Axes or anything else), the following red error message appears (even if the new data series is identical to the old data series):

OxyPlot paint exception: XAxis not defined.

This happens whether the X Axis was auto-generated or added manually.

Am I doing something wrong? How to fix?

P.S. how do you designate an axis as an X or Y axis? For example when I add a CategoryAxis it becomes the X axis by default, but how could I make a CategoryAxis that is a Y axis, or swap the X and Y axis?

(I see, it's the Position property e.g. Position = AxisPosition.Bottom)

I notice that this is specifically a painting problem; if the graph is never painted on the screen (e.g. because it exists off-screen in a tab control) then I can clear the data series and repopulate it any number of times. The exception only occurs if the control is painted and then the data series are repopulated.

Edit: this is interesting, if I call PngExporter.Export(...) then the png renders correctly. Not only that, but if I repaint the OxyPlot.WindowsForms.PlotView after exporting, it draws properly again.

P.S. Other than this problem, this library is fantastic! I love the various automatic features like fact that the graph automatically figures out the extents of the graph and that the data series automatically conforms to whatever Axis I add.