How can I resolve the warning on Autograph is Tensorflow?

Question

I was following a tutorial on YouTube about Tensorflow, and an unexpected warning on Autograph occurred. I understand that warning is not an error and that it would not affect the results, but weirdly it seems to have restarted my whole code and I couldn't run the next cell.

• Here is the link to YouTube Tutorial.
• Here is the link to the code illustrated in the tutorial on Github.
• Here is the whole Warning message Warning message description

I have also converted all data into float type and it still won't work. Just wonder how to fix this so I could move on...