Previously I didn't have auto wiper.

 

When the wiper is set to intermittent position, it will have a longer delay if the car isn't moving. When the car get back to speed, it will return to the intermittent setting.

 

 

I have retrofitted auto wiper by adding the sensor. Auto wiper works but it doesn't have this capability to slow down the wiping when the car is stationary. It just keeps wiping during  rain. Is this the way it is?

Depends on the sensitivity level set, if it's hyper, then it won't stop.

The intermittent function was slowing down the wiper while stopped because it was guessing that there would be less rain on the screen, so it wouldn't need wiping so much. The automatic wiper can see how much rain there is on the screen, so it wipes it when it needs it, without needing to guess. If you've stopped, there should be less rain falling on the screen so the auto wiper should wipe less often.
I have the auto wiper set to either the least or second least sensitive setting.

Thanks, I didn't know the sensitivity settings work for auto