I just got a JVT-59 two days ago to go with my HD PRO and while using workbench with the HD PRO Edit program I tend to have blank values in the Input selections for both inputs. When I restart the HD PRO Edit program it will show up again. Not sure if anyone else has had problems with the two. I've also had it when editing guitars in workbench and select out of phase between two pickups that I loose sound from the high strings g-b-e till I switch too a different setting and go back.
Sorry still learning how all of this works together to make for the setup I've always wanted with one click chaning everything.