That model can be picky sometimes. Mine started grinding like that after a week, turned out the blade assembly wasn't seated right. I took it apart, cleaned everything super well, even used a bit of food-grade oil on the moving parts – careful not to overdo it though. Put it back together and bam, quiet as new.
If that doesn't work, it might be a defect from the factory. Worth a shot before sending it back. Works great now.
