Problem with accuracy

Hello, 

I have been following your tutorial. It seems in the video, you are getting around 0.9, but running on Colab is giving me a max of 0.4 accuracy. Do you have any suggestions? Here's a link to my colab. Thanks!

https://colab.research.google.com/drive/1T3dSEM7ZVisle9g3s6g5Y_AypNsuhph_?usp=sharing