I'm gonna throw this in even though the vehicle that had the problem wasn't even a Ford!
After trying all the Ford guys' suggestions, if the problem still exists, you might consider this. We had the same symptoms with my wife's car. The engine would shut off just like you had killed the ignition - no sputtering, surging or anything. All the accessories and gauges were still working/reading just fine. It wouldn't restart until the key was switched off, then back to on and start. At that point, it would start immediately and run like nothing ever happened - until it quit again. The problem was a cracked motherboard in the ECU.
2016 Ram Longhorn 3500 Dually 4x4 CCLB, 385/900 Cummins, Aisin AS69RC, 4.10
2014.5 DRV Mobile Suites 38RSSA #6972
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