QML QtWebEngine system combobox drop-down placed at wrong coordinates

I create a WebEngineView at (0,0) and then later move the X coordinate to make room for a vertical toolbar on the left (user can turn on/off). The WebEngineView moves to the right fine, but when a drop down button on a combobox is selected, the drop down is placed at the wrong X position. It appears to not be using the new X coordinate, but instead is calculating its position based on the original X coordinate (when the WebEngineView is created).