JavaScript - window.scroll({ behavior: 'smooth' }) not working in Safari

As the title says, it works perfectly fine on Chrome. But in Safari, it just sets the page to the desired top and and left position. Is this the expected behaviour? Is there a way to make it work nicely?

Use smoothscroll polyfill (solution for all browsers), easy applicable and lightweight dependency: https://github.com/iamdustan/smoothscroll

Once you install it via npm or yarn, add it to your main .js, .ts file (one which executes first)

import smoothscroll from 'smoothscroll-polyfill';
// or if linting/typescript complains
import * as smoothscroll from 'smoothscroll-polyfill';

// kick off the polyfill!
smoothscroll.polyfill();

Behavior options aren't fully supported in IE/Edge/Safari, so you'd have to implement something on your own. I believe jQuery has something already, but if you're not using jQuery, here's a pure JavaScript implementation:

function SmoothVerticalScrolling(e, time, where) {
    var eTop = e.getBoundingClientRect().top;
    var eAmt = eTop / 100;
    var curTime = 0;
    while (curTime <= time) {
        window.setTimeout(SVS_B, curTime, eAmt, where);
        curTime += time / 100;
    }
}

function SVS_B(eAmt, where) {
    if(where == "center" || where == "")
        window.scrollBy(0, eAmt / 2);
    if (where == "top")
        window.scrollBy(0, eAmt);
}

And if you need horizontal scrolling:

function SmoothHorizontalScrolling(e, time, amount, start) {
    var eAmt = amount / 100;
    var curTime = 0;
    var scrollCounter = 0;
    while (curTime <= time) {
        window.setTimeout(SHS_B, curTime, e, scrollCounter, eAmt, start);
        curTime += time / 100;
        scrollCounter++;
    }
}

function SHS_B(e, sc, eAmt, start) {
    e.scrollLeft = (eAmt * sc) + start;
}

And an example call is:

SmoothVerticalScrolling(myelement, 275, "center");