2019 Cascadias, fleet with issues, any fixes?

[Waterloo]

Alright, this is a wide open question, with no real particulars. My company on their Canadian side has company drivers and company trucks. They do not compete with us...

Owner of the company just bought 15 new Cascadias with the DD motor, OTR trucks with the nice sleepers, assuming the DD15 motor, but could be the 13. All are having fuel related electrical issues. Dealership is blaming the fuel these trucks are running for the frequent shutdowns. Doubtful it is the fuel, as they fuel with all of the regular outfits out here on the road.

Any thoughts, and I wish I knew more. But, I am assuming this is a regular issue with these trucks and motors, it can't be just these 15 trucks? Any thoughts would be appreciated.