Hmm I don’t know why but for some reason instantiating from the same module causes this error. If you create one instance per nn.Sequential it does work.
Internally the id of
id(self._modules['gen_energy']._modules['0'].weight)

is the same than
id(self._modules['gen_theta']._modules['0'].weight)

Soo it’s somehow recognizing that when generating the params.
If you want to do that you need to deepcopy the nn.Linear