Hi! This sounds like your voxels are really large but it's hard to say without seeing your results. Are you able to share any pictures?
So the first image is the mask that currently existsThe second image is using the "automatic position map", with no blur amount. Currently I have no idea how to increase the voxels for the blur.
Ok cool, so the way you increase voxels is by limiting the area that gets voxelized. You would make a hidden mask with an anchor point on it and provide that to the Voxel Mask input on 3D Blur.