ScrollIntoView breaks the overflow scroll

I have a nested child container and when I’m trying to scrollIntoView it breaks the parent container. I’m not able to understand why it’s acting like this. Please help me out in this.
Please have a look at the code below or on jsfiddle

function moveToTop() {
  console.log('MOVE TO TOP::');
  const child = document.getElementById('child');
    behavior: "smooth"
#parent {
  background-color: blue;
  padding: 10px;
  height: 500px;
  overflow: hidden;
  display: flex;
  flex-direction: column;

#scroller {
  overflow: auto;
  padding: 10px;
  background-color: red;
  flex-grow: 1;

#child {
  height: 10000px;
  background-color: green;

body {
  overflow: hidden;
  color: #fff;
  font-weight: bold;

button {
  position: fixed;
  bottom: 20px;
  width: 140px;
  left: 20%;
  right: 0;
<div id="parent">
  <div id="something">Something</div>
  <div id="scroller">
    <div id="child">
      <button onclick="moveToTop()">Top</button>

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