I got 2 exercises wrong on the grading while the jupyter notebook gave me passed, Which is Exercise 3, 4
Hello @Ahmad_AlModhayan and welcome to the Deep Learning community!
First, Unit tests are commonly meant to help you spot the error earlier in your assignment but sometimes they fail to spot the error hence you can get a unit pass despite of having an error in your code.
From your second screenshot, I guess you might have a function in your code that is supposed to return a value but is returning None instead.
Happy Learning
Isaak