Juanjo - also
Which basket are you using? The original which came with he machine or the one which came with the PF?
Do you have a link to the portafilter you bought?
Also, watching the video again, in my opinion, the user is overfilling the basket. You can tell as the tamper sits quite high on the basket after tamping. If the coffee puck touches the screen, it will push the PF/basket down, get in between the lips of the basket and spray like you are seeing. So it’s important the gasket and basket are clean to form a proper seal.
The other thing I could think of is that there’s a manufacturing defect with a particular batch: maybe the lugs are too thick? Hence not locking at 6 o’clock like the video. Or maybe they are at an angle?
The thing is, is that the portafilter only holds the basket against the gasket, forming a seal. So the seal is between the gasket and the basket, not the PF.
