From Jeju’s POV, I can see “we followed Step X in the troubleshooting manual, it held up for Y timeframe, then something ELSE broke…” You could try swapping out the whole engine, but a. that takes quite a few manhours, and b. takes a money-making plane out of rotation for awhile…
Either way, will keep my ear to the ground, cuz it definitely hasn’t gotten to the end of the rabbithole yet…
Regards