As it happens, I just started a new coffee that exhibits the same characteristics.

Solution: change from double to triple basket and brew 22g of coffee. It still runs a bit fast, but it's yummy.

With no triple basket, try to cram as much coffee as possible into a double basket so that it just gets the smallest imprint from the shower screen on lock in. Iterate grind and dose adjustment until a reasonable flow gives a tasty shot with lots of crema.

that's right. I've got 16g of coffee and a pretty fine grind setting just to get into the middle of the green on the pressure gauge. But look how slow the extraction is. I'm at 34 seconds in the video and barely have a bit more than 1/2 an ounce.

I was told not to by the company I bought it from because the back flush pressure test was at the correct level (9.5 bar). They said it was likely an issue with my grind. But I've tried 2 different types of coffee and the only way I can get the extraction time right is to totally kill the pressure. I've tried finer grinds with the same volume; coarser grinds with way more volume; coarser grinds with the same volume. Nothing seems to yield 9 bar pressure and a 25-40 second extraction time for a 2oz shot. It's driving me mad.

Chris's Coffee is sending me a new pump just to make sure. But I'm sort of thinking of just returning it and getting something different.

Does the gauge flutter on a blind basket?

Is there an air bleed line on the pump output? These, particularly plastic ones, sometimes give trouble.

Unfortunately, I'm out of town for a week so I can't check the back flush fluttering, but I believe so. I was told some fluttering is normal for the type of pump used by the Dream. But Chris Coffee thought my fluttering was excessive and is sending me a new pump.

This is what the pump line looks like. Can't tell if there is a bleed line or not.

I think that's the OPV outlet. The pump is behind. The air bleed would be on the end of the pump outlet and the high pressure line feeds into it.

Fluttering can be caused by water in the gauge feed tube. If it's not soldered to the gauge, it can be removed and blown out. Otherwise, heat it to evaporate the water.

I am facing the exact same issue.

How did you solve it in the end?

I am using a hg-1 grinder with beans that pulled ok on other machines.

Basically I have gone even way way finer than I ever had to on 51mm/57mm/58mm basket, but just am not building pressure.

Backflush disc in, I can reach 9bar.