The flush is weak or sluggish.
Here's what happened: when you press on the flush lever, it pushes down on the cartridge, which starts the flush. However, in your tank, the lever cannot touch the cartridge.
- Loosen the setscrew (this may be located on the side or on the top of the actuator).
- Turn the actuator counter-clockwise approximately half a rotation. The actuator should raise.
- Flush the toilet.
- Does it flush properly?