Same issue here...2012 Overland V8 4x4...happens when slowing down (braking or coasting), sometimes when turning wheel (other times going straight)...but not frequently...very intermittent & no warning, just steering gets hard & RPM's drop to Zero...push Start/Stop & fires right back up.
Has had all recalls completed, including Fuel Pump relay & Crankshaft sensor replaced.
No engine ECM codes, so no evidence of it occurring, so dealer doesn't know how to proceed at this point...being it's difficult to replicate/duplicate & witness by a technician.
Love my Jeep, but it's concerning...in that if my wife is driving, or if we have kids in future, will it be safe to have them in it??
May have to dump it in near future & look at a 2018 Raptor or Cayenne instead, unless FCA can prove their quality & customer service improves enough to trust them going forward on another JGC.
Sad, but unfortunate & true...as too many owners are having these issues.