Please check the following steps when you feel that the suction is performing weakly:
1 / Ensure that the device has adequate, solid contact with your skin.
2 / Check that the device is on an appropriate suction power level. There are 5 suction strength intensity levels (1 being the weakest and 5 being the strongest), which can be switched by pressing the power button while the device is turned on.
3 / Check that the foam filter is positioned correctly inside the suction base, and not clogged with debris. Replace with a new foam filter as needed.