i gave my core certification test and i got a failing grade in vision and alarming. before submitting test i have cross checked each and every answers but still failed in them. I am sure that 80% of my answers are 100% correct minimum. anyone faced issue like this.
I would reach out to the training department to see if they could tell you what is actually wrong. I don't know if they will do that, but it is worth emailing or calling about if you feel your answers are truly correct.