If the grinder is new and you can send it back then I would do that, your pressure needle is not getting ‘stuck’ on preinfusion, the coffee in the basket is simply not providing enough resistance for pressure to build which is why water is gushing through and hence the need to grind finer. As Dave said above, your shot against the blind filter shows the Elizabeth is working properly.
Maybe a hand grinder whilst your waiting for your Niche to arrive, JX-pro or similar? Dialing in espresso on a hand grinder can be a little tedious but you won’t have to do it for long!