Results in Extent, Not Mask in Model

I have created a model with Model Properties--> Environments--> Raster Analysis-->Mask set to the polygon that contains the data points. The Spline with Barrier functions in the model continue to return rasters that are outside the polygon, to the processing extent of the polygon mask. When the rasters are reclassified in the next step of the model, the mask is applied successfully. All data points are contained in the polygon mask.

Please let me know if there is a workaround for this.

Thanks,
Justin