According to Max Weinbach, the Galaxy S20 series will set to a 60Hz refresh rate by default instead of 120Hz. We have also overheard the rumors that the Galaxy S20 series could not support 120Hz at the Quad Hd+resolution.
Samsung is looking to optimize the battery life of the device. That’s the reason why Galaxy S20 phones set to default Full HD+ resolution instead of Quad HD+.
If you want to try the smoother animation and scrolling experience, you can go into the device settings and manually change the refresh rate of the display to 120Hz.