american standard actuator bounces

I replaced the actuator(flapper) on a 17 year old american std tank and it keeps bouncing up & down as it tries to seal. At first I though it was from the waves made as water fills the tank, so I tried slowing down the rate of flow into the tank. But the problem persists. Any help or suggestions would be appreciated.

I had the same problem, just started recently after I replaced the actuator with the OEM replacement part.
I solved the problem by ditching that piece of junk (AS Lexington model) and replaced with a toto. Only thing I regret was not doing it years ago.

I would clean the ports under the rim inside the bowl. Use a piece of coat hanger wire and push it into each one. Also make sure the sipho jet at the bottom of the bowl. If you are using an in tank bowl cleaner such as the infamous blue glop get rid of it!