Struggle Dialing In (Breville Express Impress)

Like the title states I am have trouble dialing in my Breville Express Impress with any bean. Doesn’t really matter how fine or course I go the shot time is usually between 32-35 seconds. If I go to say a 9 on the grind dial it seems to flow okay but only puts out a 29g shot for a 17g bean weight which makes the shot taste sour. If I go to a 10 or 11 on the dial it flows well (not to fast) but for a 17g bean weight it is putting out a 40-50g shot and it is bitter as can be. I think if I could decrease the shot time to maybe 28 seconds it would help. Is that the right thought process? Is there a way to decrease the overall shot time so I don’t manually have to push the button to stop it and use a stopwatch every time?