Flushing problem

Ever since I replaced the flapper, my toilet does not flush normally. It wants to continue flushing for several seconds before the bowl begins to fill back up. Any idea what the problem could be?

You installed the wrong flapper OR You had the wrong flapper in there and now it is flushing right?

My guess is you put in the wrong flapper. What brand and model is the toilet and what Brand and kind of flapper did you put in.

My husband said he put in the exact same flapper as the old one we took out. To me it appears that the flapper does not go down as quickly as it should after the tank is emptied. My husband, on the other hand, doesn't think that there is a problem and refuses to look into it. I am just concerned that we are wasting water unnecessarily. Do you think if I attached a quarter or something to the top of the flapper that it would help? Or do you think I should take the advise of my husband and not worry about it?