There seems to be a lot behind the scenes you haven't or aren't divulging....
How many total hours did you spend training on the position?
did you time and time again get extensions or have your hours reset?
We're you passed by multiple people who certified before you?
If this isn't you your first rodeo, are you saying the training process has been unfair to you before?
All of these are generally red flags.
Then again I don't know your situation, but I've heard this argument before And the devil is in the details.
It's the ones that have to argue every training session and constantly defend their performance, that don't belong in the job. Sometimes we have to take a good hard look at ourselves first.
good luck.
And sometimes we work with assholes that love to find a target and get off on washing them out.