I’m not sure if basic_model and model_128 refer to Model5Layer_128, but if so you should be careful about putting the child modules into an nn.Sequential block.
nn.Sequential is used for simple models, where each operation can be expressed via an nn.Module.
In your Model5Layer_128 you are using the functional API (F.relu, x.view, and F.softmax) which will not be added to the final model.
The better approach would be to create a new custom modules and define the forward properly.