"There was a fault in the system which, when a female passenger checked in for the flight and used or was given the title ‘Miss’, caused the system checked her in as a child. The system allocated them a child’s standard weight of 35 kg as opposed to the correct female standard weight of 69 kg."
So titling it "Root cause: adult females checked in as 'Miss'" is wrong. The linked article does not even have the word "root".
I also assumed that the the title had been editorialized/was click-bait until I read the pdf and the incident was filed and issued by the AAIB as a 'Serious Incident'.
Which is understandable given that the flight was 1,244 kg overweight at take off due to a programming error that assumed a 'Miss' = 35 kg / passenger instead of the correct average weight of an adult female of 69 kg.
True that the actual incident was a lot different than the title suggested (and I assumed) but taking off a ton heavier than what the manifest stated is a ‘bit of a problem’ to use the English art of understatement.
> UTC AAIB Bulletin: 4/2021 - G-TAWG - AAIB-26814
So creating a title to describe it would have always been required.
The mistake was how their software reasoned poorly about passengers with "miss" as their honorific.
So it's more appropriate to say that checking in as "miss" was what exposed the problem, not that it was the root cause.