apparently the hall sender always pops up under diagnostic. I wouldnt worry to much.
I work for BMW our older petrol engines have similar problem being crank shaft sensor. Ok till warms up when hot cuts out and doesn't start. They split and open up at operating temp ok when cools down a bit. Doesn't log any faults either, my old mk3 gti also had fault when driving car felt like cut out for split second when driving. When sold lad said would start that also turned out be crank sensor.