RPM Fludder while sitting at a Stoplight

I have a 2018 IM and I noticed that flutter right away. I guess that is normal since mine did that the day I bought it.

Yes, it's normal.

Is the air conditioning on?

Mine does that too but only with the AC off. (2017 iM with 32K)

Just wanted to chime in on this "issue." I just bought my 2018 Corolla iM last week and noticed the same thing at stop lights or when the car is idling but only with the A/C on (will idle up to about 900 RPM then back down continuously while idling). RPM's are fine and no fluctuations with A/C off. It's unusual for me, but I just visited the Toyota dealer this morning and the Service Advisor told me it is normal for the car to do this. Wife's 2016 Corolla sedan doesn't do it when A/C is on so that's why I went in right away to get Toyota's opinion. Now that I read other responses here it seems like it's normal for our cars to do this.

It happens to my boy too, i have a 6 speed though. With A/C off it will drop to about 500rpm and then bump back up to 900rpm, and kind of bounce between the two until it had a happy, yet grumbly 600rpm idle. It happens more when the engine is cold for me, i can't talk for when the A/C is on because i usually drive with the windows down.

2016 with 22k miles btw.