1. The default setup of Parallels or Fusion on a Mac is supported. Please note that the performance of your Autodesk product will be slow because you are basically running Mac OS to run a Windows OS that is running an Autodesk product.
2. This default setup of Boot Camp is also supported. When you use Boot Camp on your Mac, you are partitioning your drive. One part is the Mac OS and the other part is the Windows OS. You will have the best performance when running your Autodesk software because you are running Windows OS. The only disadvantage is that you can't switch back to the Mac OS without rebooting the computer.
3. The last setup is an 'Advanced' setup of Parallels or Fusion and is not supported and this will cause problems with your Autodesk product. You are using Parallels or Fusion to 'point' to a Windows Boot Camp partition.
If you run your Autodesk software in native Windows mode (Boot Camp) and Parallels/Fusion, the licensing will break and fail. Basically, the Autodesk software doesn't know if it was licensed on the Mac OS "System ID" or Windows OS "System ID".
If you don't want to reinstall the Windows operating system on the Boot Camp partition, you may try the following workflow to get your Autodesk product running again. After fixing it, you should not use Parallels or Fusion to point to a Boot Camp Windows partition to run an Autodesk product.
There is really no need to use Parallels or Fusion because technically, you can license and run your AutoCAD on the natively on the MAC or Windows. Just remember to use the correct Product Key when installing it.