The drain mechanism is still intact. It opperates up and down, but the down is not far enough down to seal the drain and prevent the water from draining. Like the others I have turned and turned the stopper, but it hasn't fixed the problem. What's next?

The drain mechanism is still intact. It opperates up and down, but the down is not far enough down to seal the drain and prevent the water from draining. Like the others I have turned and turned the stopper, but it hasn't fixed the problem. What's next? Look down at the seat and remove any trash that may be stopping it from closing.
Good luck, Tom