My 5.5 years in aircraft instrumentation knows that most airspeed indication problems are caused by the pitot tube heater not working. But this was in a warm climate and I don’t think they got very high where the air would be cold, so maybe not in this case.
I can’t recall the details (and leaving for work), but I recall a report of wasps nesting in a pitot tube.
I agree with others’ comments re maintenance problem: There were warnings and they were not heeded, defect or not.
‘But this was in a warm climate and I don’t think they got very high where the air would be cold, so maybe not in this case.”
3 minutes into a flight, I’d agree with you, but at 13 minutes into the flight (the case here), the air would be quite cold, assuming a normal climb.