Grinder keeps stalling

Question

We have a virtuoso Burr Coffee grinder, just bought. We set the grind to about 10, and hit the button. After a few seconds it stalls. We have to stir the beans, then it goes again, then stalls. We have tried various settings, from 5 to 15 but same thing happens. Are our beans too oily. What do you recommend we do?
Thanks