If there is breast milk trapped under the diaphragm chamber, please refer to the following reasons:

• The diaphragm chamber is designed to prevent backflow and leakage from the flange tunnel that may wet mom's body and clothes, and a minor trade-off for this design is that it might trap a tiny bit of breast milk in the groove where the diaphragm sits. 
• With the current diaphragm chamber design, it is recommended to remove the pump hub from the container and keep the rest of the components (including the diaphragm) assembled to prevent leakage when transferring the breast milk. Additionally, please tilt the container with the flange up when pouring the breast milk. 
• Remove the diaphragm to collect any trapped breast milk, if necessary.

If you have any further questions regarding the eufy Breast Pump, please don't hesitate to reach out to us for assistance.