Solved by ptrblck in post #2 
              
              
                The convolution operator in PyTorch is a cross-correlation and not a convolution in the signal processing sense. 
From the docs: 

[…] where ⋆\star⋆ is the valid 2D cross-correlation operator, N is a batch size, C denotes a number of channels, H is a height of input planes in pixels, and W is width …