I have gone through the same issues. Two potential causes. First, the RCM. It takes 5 minutes to remove it and check the solder joints for issues or just send for repair ($30 by DJ) or buy a new one from Rock Auto for $124.

The other cause can be the Crankshaft Positioning Sensor (CPS). Easy to replacr and about $25 at Rock Auto.

After fixing my RCM, still had the issue, so bought the CPS.

Good luck.