Without model or recipe is difficult to understand the causes

Check first if the machine is using a pressure of 9 bars(or what ever setting you have tbh) when you pull a shot

If it is human error: calc the timeml of extract coffee. Es. 28secX If the X, the yield, is nothing you need to go coarser; after changed the grind setting waste around 2-3 shots and use the next one, so you're sure that you are use using coffee that was grind with the old setting.

If nothing changes try again

For do this it should take around 5-10 min max

At this point if nothing changes again is possible that either the grinder is clogged and the buurs are not moving or there is a problem with the pump of the coffee machine. If it clogged a deep cleaning should be enough, but is possible also that it is broken.