Thanks for the update. I don’t know, how your models are defined, but this minimal code snippet works fine:
#include <torch/torch.h>
#include <iostream>

struct NetImpl : torch::nn::Module {
  NetImpl(int64_t N, int64_t M)
      : linear(register_module("linear", torch::nn::Linear(N, M))) {
    another_bias = register_parameter("b", torch::randn(M));
  }
  torch::Tensor forward(torch::Tensor input) {
    return linear(input) + another_bias;
  }
  torch::nn::Linear linear;
  torch::Tensor another_bias;
};
TORCH_MODULE(Net);


int main() {
  auto net = Net(4, 5);
  for (const auto& p : net->parameters()) {
    std::cout << p << std::endl;
  }

  auto net2 = Net(4, 5);

  torch::save(net, "tmp.pt");
  torch::load(net2, "tmp.pt");
  for (const auto& p : net2->parameters()) {
    std::cout << p << std::endl;
  }
}

and I can properly save and load the model.