Design fault.  Obviously those idiots savants so highly educated forgot some basic principles somewhere... Boeing lead the world in its production line, with the concept that a group built the aircraft from scratch, and was then responsible for all maintenance and upgrades, rather than the assembly line of one person doing one job endlessly.

As a result their warranty repairs etc fell by around 90%+ ... so something has gone wrong......

Either they have abandoned this proven method or their NERDS are failing to understand that physical things are not mental ideas and have certain boundaries.  Apart from that, anyone who owns a computer can see that over-technicalising something always has gremlins in it.... little widgets that play up for no real reason.

We saw the same with Scarebus for a while, but they seem to have overcome their early failures.

** NERDS - Notional Extraction and Rational Derivatives Specialists - a term I designed for my WW IV series.  Above my pay grade.... I'm only a General here.... leave it to Rowdy and his college kids....