Thanks anyway. I put in a ticket with Presonus to see if I can get this resolved. I got absolutely nothing from their Forum. I can’t figure out what’s missing. They can both see each other and I can pass audio in both directions. I can even get DAW mode to launch. But then it’s just a blank screen on the desk.
You’d have thought they could have made at least ONE video showing how to use it with a different DAW, since they’re advertising this as a feature. But hey, Avid says their hardware works with Nuendo too. 
So, I guess all bets are officially off with those old “Truth in Advertising Laws!”
I really hope that I can get this resolved. With this one exception, I love this desk! But this one exception is an absolute deal breaker!! So, if we can’t get this to work with Nuendo, it’s going back to the store.