An symmetrical uniform shape is not the best object to do a test scan,
with scanning it really is important to have an object that has uniform matt color, and have a no parts of the object that look the same.

with the rubics cube, the black parts and reflective color stickers can cause a lot of problems.
and also, because the sides of the cube look the same to the software, it will have problems aligning the scans, the software needs reference points to see where it can stitch the next scan, of that looks the same as before, it can cause terrible artefacts.
if you really want to scan the cube, just stick painters tape all over it, and re-scan, you will see a major difference.