add node cause result wrong!

[NotOnlyAI]

    identity = x.features

    out = self.conv1(x)
    out = out.replace_feature(self.relu1(out.features))

    out = self.conv2(out)
    out = out.replace_feature(out.features+identity)
    out = out.replace_feature(self.relu2(out.features))

if without "out = out.replace_feature(out.features+identity) " ,the c++ and pytroch result is same . if has out = out.replace_feature(out.features+identity) result is not same ? why?