SpaceX engine issue on last Starlink mission caused by cleaning fluid according to Elon Musk

SpaceXCEO and founder Elon Musk said on Twitter on Wednesday that the cause of the failure of a single Merlin engine during the most recent Starlink launch (which didn’t prevent the launch from ultimately succeeding at its mission) was the result of an undetected, “small amount” of a cleaning fluid that ignited during the flight.
The SpaceX Falcon 9 vehicle uses nine Merlin engines on its first-stage, and can still operate successfully in case one stops working. One did stop wo