Couple of things, are you using the pressurised baskets? if so, you don’t need to tamp with any pressure at all.
but, firstly, do you get water with no portafilter in place?
If so, then add the portafilter with no basket, and then with basket to see if you can isolate the problem.
but, it could be an air bubble in the system, try running a full tank through the steamer, with both steamer and pump buttons on.
if not, it looks like you’ve got a dodgy solenoid. you can dismantle and fix, but I’d send it back.
I sent my classic back to Amazon for a dodgy solenoid, got a replacement within two days, been spot on ever since.