In the years since, manufacturing problems have emerged[1] not only in the 737 but at other factories where Boeing makes its 787 Dreamliner, a U.S. military refueling tanker and Air Force One replacement jets[2], as well as at some of its key suppliers.
https://www.wsj.com/business/airlines/boeing-manufacturing-7...
[1] https://www.wsj.com/articles/boeing-dreamliner-delays-faa-de...
[2] https://www.wsj.com/articles/boeings-new-air-force-one-hit-b...