Thank you for your reply about Batchnorm autograd.
But I think I didn’t have a perfect explanation on the second question.
My question about V2.0 and V1.0 is that why V2.0 works?
It seems that it is using in-place operation which should raise an error while running(mentioned in this same link 5).
But in my case, both version is working? I am curious about that.