Hi Andrew. Your script works fine with the addition of this line:
ServArea.defaultImpedanceCutoffs = [1]
Seems like you shouldn't need this because all your facilities have explicitly-set break values in the Breaks field, but for some reason it's getting confused. I'll log a bug on our end to address this item of confusion, but I think if you add this to your code in the part where you're setting the service area properties, you should be good to go.