When WebEngineView is placed inside a component that has decimals defined for margins, the content of the view is rendered with artifacts like shown in the attached image. This is working correctly when using integers. The problem can only be seen on the non-HiDPI screen, on a HiDPI display (M1 macBook) the web content renders correctly. The content is also rendered correctly on Windows.

The following code can be used to reproduce the issue:

import QtQuick
import QtWebEngine

Window {
    width: 640
    height: 480
    visible: true
    Item {
        anchors.fill: parent
        anchors.leftMargin: 3.5 // works with leftMargin: 3
        WebEngineView {
            anchors.fill: parent
            url: "https://www.qt.io"
        }
    }
}