Are you using a double floor basket or the single ?
Remove the basket and look to the light... *If you can see only one small hole; then your using the pressurised basket- Note: SB even mention this on page 8 of the Instruction manual.
1: *What grinder ?
2: *What grind settings ?
Many people think it is all a simple process, however as you will learn... There are a few simple steps such as;
1: Fresh beans
2: The grind
3: The tamp
And this will make all the difference. *From there you can stop if your happy or keep tweaking in an effort to get the best from your machine.
Welcome to CS...
Where are you located ?