If you want to reload the model you can use the mx.gluon.HybridBlock.imports() function: see Load params from Symbol models to Gluon
If you just want to reload the parameters of your original model, the simplest is to rather do
net.save_parameters() and net.load_parameters(). There is backward compatibility in place so that you should potentially be able to do a net.load_parameters() on the exported parameters but in case of complex nested network and custom export function that might not work all the time. If you share your full code snippet we might be able to help you better.