`scroll-behavior: smooth` does not work

[Soyn]

Hi, after i add the scroll-behavior:smooth to the ps container. The scrollbar will not work as expected. The scrollbar will be moved after mouse move. And it's okay after i remove the scroll-behavior.

Following is the performance image with no scroll-behavior. What i get is the less work will be done if no scroll-behavior. If use 'scroll-behavior', mouseMove handler will be triggered multi-times. I think that's the issue.

No scroll-behavior:smooth

Use scroll-behavior:smooth

Following is the profile files. (Check if you need)
profiles.zip

Demo script in jsFiddle: Demo