Description
In the DSP Builder Handbook, Volume 2, Chapter 4: Using MegaCore® Functions, it identifies that when adding a MegaCore function to your Simulink® model, you must give the block a unique name and recommends that you rename all blocks representing MegaCore functions.
One consequence of not renaming the MegaCore function is that your HIL co-simulation may not match your Simulink simulation.
Resolution
Be sure to rename all your MegaCore functions to unique names.