If the spaghetti has been falling out of the roof at about 11,000ft, it would indicate to me that the pilots have been forgetting to turn the bleeds on after take off.
Three similar events in a short period of time is pretty serious, particularly if the events weren’t isolated to one aircraft.
Been at least one King Air accident in Australia, where the pilot may have forgotten to put the bleeds on and ended up crashing on the other side of the country due to hypoxia.
Transition scan and checklist should capture the bleeds if they have been forgotten, pilot fatigue isn’t an acceptable reason for this in my opinion. If it is, why haven’t they had three gear up landings?