Popup Menu opens at the wrong position in QQuickView embedded in QWidget

I have created two QWidget elements from two QQuickView elements using QWidget::createWindowContainer(). My widgets are inside my main window and do not fill the entire window. Each QQuickView element contains a Menu element that I open on mouse click using Menu.popup(). For the second of my QQuickView elements, the menu opens on the wrong place. Actually, it opens at cursorPos + My widget's position in its top-level window.

Additionally, I see some strange effects before the menu opens for a second QQuickView element: part of the menu appear and quickly hide on the first QQuickView element.

Note: I saw similar issues which have been marked resolved.

I am on Windows 10 with two screens.

Example code can be found in the attachment.