... washing the (head of the) plunger after using it to tamp the grounds (as shown in the video 'basic operation and maintenance' in the support section). What is not showing in that video or the FAQ is that there is a rubber valve in the plungers plastic head, see my picture. If that valve is not working (allowing air to pass through), the water runs straight through the chamber making usual coffee because the plunger is not able to build up pressure. The solution was to push the valve up carefully, take it out and clean/dry it before putting it back in. That should be documented in the FAQ and the valve be available as spare part (in the event that grounds are stuck in it)...
Despite that experience a wonderful product with a great design. I'd wish the capsule sleeve's piercing needles for coffee pods would be a bit more sturdy, some pods come with a thicker wall, so the needles of this cage sometimes bend, not able to pierce the pods' wall - I need to use a reamer or needle to pierce the pod manually. (My SP-200 has no piercing needle in the gasket like shown in the video but a separate capsule sleeve instead.)