[Darryl Ramm]

I doubt most people can follow what you mean with "then starts using Internal settings..."

When you say switch off are you shutting down the OS and powering off the computer entirely or do you mean sleeping the computer then later wake it?

I expect you mean the earlier, but if the later--don't do that.

Where is any hard information here... like the Duet driver version you are running? Mac details, etc. Is the interface directly connected to the Mac or into a hub etc.

Did you do an insitu upgrade or a full clean install of Sierra?

If it was fully shutting down, make sure macOS is not configured to use the interface, unplug the interface and plug it in with the computer powered on does then it work?