Hi all. I have the same problem with a D430 & D400 combination (also with a D410&D400 combination)–the PCB-only version of the cameras–under linux (Ubuntu 18.04).
Equally, realsense-viewer works perfectly but all NuiTrack examples fail. Attaching directly to a USB3.1 port with a good cable (3.1), however, does not do any difference.
Ubuntu 18.04, Firmware: 5.10.3, Latest librealsense2 (2.15.0), GA-SBCAP3350