If everyone in the country had the "certain hairstyles we'd have no problem saying "this machine doesn't work".
And frankly I don't think anyone who knows a lot of African-American Women would even consider asking them to change their hair.
Some hairstyles are just bunched up and the machine can't tell what it is, so it gets flagged for manual inspection.
This is not a problem that is easily solved with technology.
Your only options are:
(1) not checking anyone's hair
(2) manually checking everyone's hair
(3) letting the machine do it's job and accept the fact that it can't scan certain hairstyles.
On the contrary, it would be easier to say that the machine does work because it does flag down people who have suspicious body features regardless of race.
People of African descent have a propensity towards the problem hairstyle that skews the results.
If your argument is for 'de-racialization' then you need to convince people to change their hairstyles to make everyone more similar.
You can't blame a machine for treating a 1 as 1 and 0 as 0.