Solved by Naman-ntc in post #2 
              
              
                Just in case someone falls upon this, you may find this discussion useful. 
Also I finally shifted to reshaping to 4D tensor for BatchNorm2D (the original) and reshaping back to 5D after it. 
class myBatchNorm3D(nn.Module):
	"""docstring for myBatchNorm3D"""
	def __init__(self, inChannels):
		super(…