Solved by Lezcano in post #5 
              
              
                The correct way to remove parametrisations (this or any nn.utils.parametrizations) is through torch.nn.utils.remove_parametrization: torch.nn.utils.parametrizations.spectral_norm — PyTorch 1.10.0 documentation 
As a side note, all this is documented in the parametrizations tutorial: Parametrizations…