@alexis-jacq sorry, didnt think it was useful  to show that, it has to cross processes, the function makes external calls outside of python  and gets back images which I then convert to tensors.  I can show if you think useful.  I have no idea how to fix this or model the problem.  But as I understand it now, I dont think its possible what Im trying to do? how can I create a relationship between output_features and outputs as outputs are the weights I need to update?