I had this with a compact unit and it turned out to be how I was loading it and starting it... Frozen berries right on the blades can make a nasty chirp that sounds worse than it is. What helped me was letting frozen stuff sit for two minutes and adding a bit more liquid and and starting with a few pulses so the blades dig a channel first. I did the two minute thaw and a splash more liquid and boom, the shriek vanished and the thing stopped dancing across the counter.
That said if it also grinds when you spin the blades by hand or when blending just water, it is not a loading problem. Try loosening and re seating the blade base, make sure the jar is fully clicked in, then give it one short test on low. If the sound persists, do not run it again. Exchange time. No shame in that, brand new gear should not make a metal on metal sound.
