Sorry for the confusion. You don’t need to use the One Page Navigation feature to achieve smooth scrolling jump links as this should be the normal behavior in our themes. The One Page Navigation option is now just a menu selection tool for a page.
I do see that the smooth scroll works in other browsers except for Chrome so there might be something specific in your site that is conflicting with Chrome. I’ve tested in my site and the jump links scrolls smoothly in Chrome as well as other browsers.
I see you’re using an optimization plugin (W3 Total Cache), would you mind clearing all caches and then deactivate it?
If that doesn’t help, please give us WordPress Login Details in a Secure Note so there’s an increased chance we see what is causing the issue.