SPHVolumeInterpolator and PointVolumeInterpolator have their 3D Bounding Box widget offset from the input data
Easy to reproduce for V5.8-RC2:
Wavelet + CleanToGrid + SPHVolumeInterpolator
the 3D cuboid widget is not centered over the volume, but appears to be centered on the 0-th point of the grid
N.B. The SPHLine- and SPHPlane- interpolators are correctly centered over the volume