Browser control over non-current tab elements.

the following code, if you keep it on the current tab, everything will be fine.
but just switch to another tab for a few seconds on the way, and then switch back and crash.
what exactly does it work?
(of course I know there are many other ways to avoid this situation, but I"d like to know the mechanism of such problems)

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }

        a {
            text-decoration: none;
        }

        .wrapper {
            padding: 10px;
            border: 1px solid -sharp000;
            width: 300px;
            margin: 0 auto;
        }

        .container {
            height: 200px;
            position: relative;
            font-size: 0px;
            overflow: hidden;
        }

        .banner {
            position: absolute;
            width: 1800px;
        }

        .banner a {
            display: inline-block;
            width: 300px;
            height: 200px;
            font-size: 50px;
        }

        .banner a:nth-child(1) {
            background-color: rgb(219, 106, 106);
        }

        .banner a:nth-child(2) {
            background-color: rgb(108, 223, 73);
        }

        .banner a:nth-child(3) {
            background-color: rgb(194, 57, 212);
        }

        .banner a:nth-child(4) {
            background-color: rgb(219, 106, 106);
        }
    </style>
</head>

<body>
    <div class="wrapper">
        <div class="container">
            <div class="banner">
                <a href="-sharp">1</a>
                <a href="-sharp">2</a>
                <a href="-sharp">3</a>
                <a href="-sharp">3(2)</a>
            </div>
        </div>
    </div>
</body>
<script>
    let banner = document.getElementsByClassName("banner")[0],
        unitWidth = 300,
        unitNum = 3

    let move = function (e, ds, callback) {
        e.move = setInterval(function () {
            if (ds > 0) {
                e.style.left = e.offsetLeft + 10 + "px"
                ds -= 10
            } else if (ds < 0) {
                e.style.left = e.offsetLeft - 10 + "px"
                ds += 10
            } else {
                clearInterval(e.move)
                callback()
            }
        }, 20)
    }

    let autoStart = function () {
        banner.auto = setInterval(function () {
            move(banner, -300, function () {
                if (banner.offsetLeft === -unitWidth * unitNum) {
                    banner.style.left = 0
                }
            })
        }, 1600)
    }

    autoStart()
</script>

</html>