Assert when using QMenu in a QPushButton (iOS)

It seems a QPushButton which has QMenu asserts on iPad Pro 10.5" (15.4.1).
This is with reasonably new Qt 6 dev.

I originally noted this when running the Qt NFC example application (ndefeditor) on iPad,
but the issue reproduces with a simple reproducer:

    auto button = new QPushButton("button", this);
    auto menu = new QMenu(this);
    menu->addAction("action", [](){});
    button->setMenu(menu);
    setCentralWidget(button);

The menu may open a few times, but ultimately clicking it produces an assert:

ASSERT: "!m_activeTouches.contains(touch.hash)" in file qtbase/src/plugins/platforms/ios/quiview.mm, line 490