Schema mismatch for label column ': expected Boolean, got Single

[robalexclark]

I have an AutoML experiment as follows:

     List<QuoteModel> quoteModels = new List<QuoteModel>();

   //...get data from db and load into quoteModels

     MLContext mlContext = new MLContext();

     IDataView dataView = mlContext.Data.LoadFromEnumerable(quoteModels);
     TrainTestData splitDataView = mlContext.Data.TrainTestSplit(dataView, testFraction: 0.8);

     SweepablePipeline pipeline = mlContext.Auto().Featurizer(
         dataView)
         .Append(mlContext.Auto().BinaryClassification(labelColumnName: "LeadWon", featureColumnName: "PreviouslyFlooded"));

     AutoMLExperiment experiment = mlContext.Auto().CreateExperiment();

     experiment
         .SetPipeline(pipeline)
         .SetBinaryClassificationMetric(BinaryClassificationMetric.Accuracy, labelColumn: "LeadWon")
         .SetTrainingTimeInSeconds(60)
         .SetDataset(splitDataView);

     TrialResult experimentResults = await experiment.RunAsync();

The QuoteModel class is:

public class QuoteModel
{
    public string PreviouslyFlooded { get; set; }

    public Boolean LeadWon { get; set; }
}

When I run the experiment it gives the error:

System.ArgumentOutOfRangeException: 'Schema mismatch for label column 'LeadWon': expected Boolean, got Single

If you look at the QuoteModel class, the label column LeadWon is definately a boolean!!

Any ideas why/how it can give this seemingly impossible error?