The 50 miles to empty is a calculated value, and might be off a gallon or so; especially if you've been towing. It's possible the fuel pump is sucking air, and you're getting air into the fuel line.

If you're towing, try to not get below 100 miles to empty.

 

When I'm towing the alert comes on right around 1/4 tank. I've towed locally and had the low level come on and not have any stall issue. This is related to what everyone else has been experiencing. Long extended towing.

 

I paid the dealership $90 too flash the PCM as specified in the TSB and I have not had the problem since. Mine is 2016; not sure why the TSB specifies 2018 and not earlier models that clearly share the problem!