'09 Dodge Ram 5.7L MDS engine stall

I have a 2009 Ram 1500 5.7L. Twice now the engine has stalled out while driving and would not start again but after sitting for a while waiting for the tow, it would start again. First time dealer did a software upgrade to a mod. It’s back at the dealer now, waiting for some attention. It started for them after sitting over night. Any thoughts?