EmilioMachado Gen1 with an old mobilenetssd model worked perfect for 3 or 4 years
But you are using the SDK now right? Could you maybe try the spatial location calculator example to see if Z axis is correct. The SDK works in the same way as YoloSpatialDetectionNetwork, which is a combination of Yolo and Spatial Calculator. Seems there is a problem with the latter.
Thanks,
Jaka