Hey all. I have a 2009 Corolla S that seems to be "shifting hard". It only seems to happen when I drive it for the first time after a few few days. It also seems to go away after accelerating once (i.e. it doesn't happen on subsequent accelerations). This is sometimes accompanied by the tachometer shooting up to around 3000-4000 RPM suddenly, without much movement from the car. I currently do not have a video or audio recording, sadly. I am not sure whether the car's transmission has ever been serviced or whether the ATF fluid/filter have ever been replaced. Do I need new fluid or could it be something worse?