Error bars don't draw and hide another series

(Edited to add code blocks)
I am trying to draw 4 series simultaneously on a chart. I have 2 Scatter plot series, a FastLineRenderableSeries (Which I’ll call the trendline) and I have a FastErrorBarsRenderableSeries which I’ll call the uncertainty. The scatter plots always draw.

When I draw the scatter plots and the trendline, everything looks right. As soon as I add any points to the HlcDataSeries in the uncertainty, though, the trendline disappears, and the error bars won’t draw. It’s very strange.
Below is my xaml and code (edited for clarity).

   void SetData(int channels, MyDataSet incomingData){
        var n = incomingData.Count;
        var unc = new List<Point>(n); //Point has x y coords and uncertainty
        double[] xValues = new double[n], yValues = new double[n];
        for (int i = 0; i < n; i++)
        {
            var x = incomingData[i].X.Value; //Incoming data has x y coords 
                                                                  //with uncertainties in each direction
            var y = incomingData[i].Y.Value;
            xValues[i] = x;
            yValues[i] = y;
            var yVal = incomingData[i].Y;
            if (yVal is not { Uncertainty: not null and not 0 }) continue;
            unc.Add(incomingData[i]);
        }
        if (xValues.Any())
            PointData = new XyDataSeries<double>(xValues, yValues);
        var xList = new double[channels];
        var yList = new double[channels];
    if (incomingData.CalibrationCoefficients == null)
    {
            incomingData.Fit(); //Generate coefficients
    }
    for (var i = 0; i < channels; i++)
    {
          xList[i] = i;
          yList[i] = incomingData.GetY(i); //Apply Coefficients
     }
    LineData = new XyDataSeries<double>(xList, yList);
    unc.Add(new Point(1, 0, 100, 50)); //x, x uncertainty, y, y uncertainty
    unc.Add(new Point(10, 0, 100, 50));//Adding bogus data to ensure uncertainty
    unc.Add(new Point(100, 0, 1000, 50));
    unc.Add(new Point(1000, 0, 500, 50));
    unc.Add(new Point(5000, 0, 250, 50));
    if (unc.Any())
    {
        UncertaintyData = new HlcDataSeries<double, double>();
        var hlc = (HlcDataSeries<double, double>)UncertaintyData;
        foreach (var t in unc)
        {
            var uncertainty = Math.Abs(t.Y.Uncertainty);
            var y = t.Y.Value;
            hlc.Append(t.X.Value, y,
                y- uncertainty,
                y+ uncertainty);
        }
    }

}

And my Xaml:

 <s:SciChartSurface MinWidth="200" MinHeight="200" 
                                   Name="ChartSurface" Padding="0"  
                                   Style="{Binding CurrentChartStyle}" >
            <s:SciChartSurface.RenderableSeries>
 <!-- Scatter plots omitted for brevity -->
                <s:FastErrorBarsRenderableSeries DataSeries="{Binding UncertaintyData}" 
                                                 ErrorDirection="YAxis"
                                                 Stroke="Blue"
                                                 StrokeThickness="2"
                                                 LastErrorBarWidth="7"
                                                 DataPointWidthMode="Absolute"
                                                 /> 

                <s:FastLineRenderableSeries x:Name="LineSeries" AntiAliasing="True" Stroke="Gray"
 DataSeries="{Binding LineData}" StrokeThickness="2"/>
            </s:SciChartSurface.RenderableSeries>
 <!-- Axes omitted for brevity --> 
        </s:SciChartSurface>