intermittent humming noise between 62-68 mph

17K miles. January 2017 on a recent road trip to Florida from NC, I started noticing a strange intermittent humming noise coming from the engine bay just below my feet where the transmission resides. The noise was loud enough to catch my attention over the radio so I turned it off to see what it could be. Between 62-68 mph, the intermittent humming noise was consistently present, with or without cruise control on. Once I accelerated above 68 mph, the noise appeared to go away but hard to say with the higher RPM noise of the engine. Whatever the noise is it even generates a vibration through the gas pedal that can be felt by the driver's foot. No check engine lights. No loss of power. Nothing else to indicate the engine or transmission is not operating properly but this noise just started at 17K miles. When I returned from Florida, I took my truck to the John Hiester Dealership in Lillington, NC to have it checked. The technician rode with me and heard the same noise. Their initial diagnosis was the after-market cold air intake was pushing too much air for the PCM to regulate at higher speeds so they replaced it with the OEM intake system. However, this diagnosis proved false as the noise returned the following day and I returned to the dealership for them to troubleshoot. The techs were unable to determine the cause of the noise and stated the truck is under warranty for the powertrain to 100k miles and they would notify Chrysler to see if the engineers possibly knew the cause of the noise. For now, I'm stuck with this mysterious humming noise coming from my transmission without any resolution found.