question: Validation step: error when trying to return object
context: Hi,
  As part of my validation_step in a AE I am trying to return an object containing input and reconstructed output.
  validation_epoch_end does not get the accumulated outputs.
  Here's the code:
  def validation_step(self, batch, batch_idx):
          x, x_recon, _, _, _ = self.forward(batch)
          outputs = {
              'x': x,
              'x_recon': x_recon
          }
          return outputs
  
  these are the shapes:
  x.shape:  torch.Size([2, 1, 257, 63])
  x_recon.shape:  torch.Size([2, 1, 257, 63])
  and this is what validation_step_outputs looks like:
  [{'x': tensor(0.0033, device='cuda:0'), 'x_recon': tensor(-0.0102, device='cuda:0')}]
  Any idea why?
  Thanks
answer: hey @mcomunita!
  this shouldn't happen. Quick ques: are you using DP?