NHTSA Complaint #11441248 — 2016 FORD EXPLORER

About 2 weeks ago I heard a noise and from that point it sounded like my steering wheel was grinding. Steering is tight at slower speeds and it is making that same grinding noise. I took it to a dealership to get checked out and was told the steering gear had failed and that it needs to be repaired however the parts are on back order with no foreseeable ship date, but that it was ok to drive, just may be a little hard to steer at low speeds. This morning my steering wheel was totally locked up and could not turn in either direction. There are no warning lights or other indication of an issue. My concern is could this have happened while driving? What caused it to break in the first place and why did it ultimately seize up completely after being told it could be driven?