why do i get the lower accuracy for this CNN example "Image Category Classification Using Deep Learning"? not like the example's accuracy is 1

https://www.mathworks.com/help/vision/examples/image-category-classification-using-deep-learning.html i tried the example, but got different results, like below: confMat =

     1     0     0
     1     0     0
     1     0     0

accuracy = 0.03...

i don't know why i can't get good accuracy... could someone help me ? thanks