When I train and save a model with the ModelBuilder from Visual Studio, and inspect the model that is loaded to predict I get a TrainSchema with all columns, and the last column is the Features column.

When I train and save a model with the AutoML API, it received an exception where it tries to find a SamplingKeyColumn. After inspection AutoML has saved the model with an additional column just before the Features column. This is different compared to the ModelBuilder behavior.

So I have to extend me model with the following lines to make sure I can run a prediction (I have 34 columns in my dataset).

        [ColumnName("SamplingKeyColumn"), LoadColumn(35)]
        public float SamplingKeyColumn { get; set; }

Is this expected behavior? It feels very inconsistent and quite confusing behavior. I couldn't find any documentation about this either.