Why auto jump to the embedded iframe

Hello, I got a problem when embedding dashboard. In case, the <iframe></iframe> is on the bottom of my page, general, we can’t see it unless scroll to the bottom. But weird, the page auto scroll to the position of iframe if I refresh page. My grafana version is 5.2.0. And you can try a demo .html with code is:

<!DOCTYPE html>

        <iframe src="https://www.cnblogs.com/hq233/p/9849939.html" scrolling="no"  width="100%" height="400" frameborder="0"></iframe>
        <div style="height: 400px;"></div>
        <iframe src="" scrolling="no" width="100%" height="500" frameBorder="0"></iframe>