Week 1, Gradient Checking assignment, fixing backward_propagation_n

I have passed the assignment with 100%, and now I am trying to fix backward_propagation_n. I found an error in the following line:
dW2 = 1. / m * np.dot(dZ2, A1.T) * 2
“* 2” should not be there.
But it still does not give me proper result because the difference is just slightly better.
Can you give us any hints of what is wrong? Are there multiple bugs?

You are very close. Your fix for dW2 is correct. And,… there is another one. Total two errors in here.

Got it. You have to read the code really carefully, but errors are obvious.