Dear Patrick, Thank you for sharing your experience with the De’Longhi Bottomless Portafilter (Product ID: DLSC085). We’re sorry to hear that it did not seal properly or build sufficient pressure, especially when your standard portafilter performs as expected. We understand how disappointing this can be, particularly for a premium accessory. We’d like to highlight that compatibility is essential for proper sealing and pressure. According to our product description, the DLSC085 bottomless portafilter is compatible only with: De’Longhi La Specialista models De’Longhi Dedica Maestro models You can review the compatibility details here: https://www.delonghi.com/en-us/p/coffee-accessories-dlsc085-bottomless-portafilter/DLSC085.html?pid=AS00009101 In addition, bottomless portafilters are more sensitive to grind size, dose, tamping pressure, and basket fill level. One common cause of low pressure or poor sealing is overfilling the basket. Please ensure that after tamping, there is at least 3–4 mm of space between the coffee puck and the top edge of the portafilter. Overfilling leaves no room for the portafilter to seat correctly against the boiler outlet, which can prevent proper sealing and pressure buildup and may cause the issue you’re experiencing. Our team would be happy to review your specific setup, confirm compatibility with your machine, and guide you through dialing in the correct dose and grind to achieve optimal extraction—or help determine the best next step if the accessory is not the right match for your model. To address the issue, please feel free to chat with a Live Expert at: https://www.delonghi.com/en-us/delonghi-support and click Chat at the bottom right. Kind regards,