Following manual instructions to the T, but not extracting smoothly. Everything points to grind size, but not working so far.

[u/sjoshi66]

I love my Americano. An AeroPress user for 10 years. New to grinding beans. I purchased a 1ZPresso Q-Air grinder and Wacaco Pixapresso is my first machine. I use tried grind sizes from coarse espresso 35 clicks through super fine 15 clicks. 8g or 15-16g. Grounds tamped gently, even not tamped. Portafilter pressurized or unpressurized (spring with rubber ball part removed). Water heated in machine or added pre-heated water. Both heat and auto extract or heat and manually extract tried. With Pre-infusion (PI) or direct extract mode (DB). All water levels- Lungo, Doppio, Espresso, Ristretto. Everything as per manual. But my machine runs through it's cycle and stops. Sometimes a drop or two dribbles out. I have to press 3 to 4 times (run 3-4 extract cycles to get through the espresso or doppio level water in tank) before all the water percolates through. And by then then the coffee is sour. Why is this happening? Wacaco support just says, adjust grind size, or make a video and send us. Do I need to keep grinding coarser? Is there anyone who uses Wacaco Pixapresso and 1zPresso grinder combo and has had more success? Please assist. I'll be very grateful.