After 37 years in aviation maintenance, everytime I hear about these boeing issues I suspect it’s a maintenance problem.....specifically lack of PREVENTATIVE maintenance.
Also, where the heck is the Quality department??? 🤷
Yes, it would be a maintenance problem, not a Boeing problem. The engines for the 737-900 are made by a joint venture with General Electric and Safran (a French Company). It is up to the individual company to maintain the engines once the aircraft is delivered.