[QMacNativeWidget] show modal breaks Qt event loop: QObjects deleteLater events not processed

Embedding a QMacNativeWidget in an NSWindow, showing a Qt modal dialog or a Qt popup such as a combobox, puts the qt event loop into a bad state where deletion with QObject::deleteLater() stops happening. I assume this is related to qt event loop level.

Test Case Attached:
My test case has a timer creating a QObject every second and marking it for deletion with deleteLater(). After clicking the combobox (any modal state will do) deleteLater objects no longer deleted.