Some Of These Intermittent Crank/No Starts Can Be The Result Of Fretting Corrosion (Dark Smudges, But Sometimes Not Even Visible Without Magnification) In Connectors For Various Modules (BCM, ECM, TCM, PCM, etcetera).
The corrosion insulates the terminals and is not a conductor. The fix is to disconnect connectors and use a nylon brush to brush away any oxidized deris and to apply a very small amount of dielectric grease before reconnection.
Did the dealer do any of this ?
CSA