Chart JS seems to be ignoring options

[Esqulo]

Im trying to customize the Y axis with fixed values between 0 and 10, showing only even numbers. When testing into de preview avaliable at the Chart JS docs, all seems to work fine, but when I use the same params in my application, the config seems to be ignored.
here is the side-to-side comparision of the same config:

I have made some research but found nothing but typos and other miss-uses that I have already checked for,
Any clue on what could I be doing wrong?