The puck sticks to the shower screen
On unlocking the portafilter, the spent puck has lifted out of the basket and is stuck to the group.
Applies to: Espresso machine, Espresso
Likely causes and adjustments
Try one adjustment at a time so you know what actually changed the result. Start with the first cause below — if it doesn't help, reveal the next.
Cause 1 of 3 · Commonly the cause
Dose too large for the basket, leaving no headroom
Reduce the dose by a gram or two and check the puck clears the screen when locked in.