Opening a browser tab in the same window on a QWebEngineView. Why is referrer not being passed?

Question

Python

There is a code:

class WebEnginePage(QWebEnginePage):

    def createWindow(self, _type):
        page = WebEnginePage(self)
        page.urlChanged.connect(self.on_url_changed)
        return page

    @pyqtSlot(QUrl)
    def on_url_changed(self, url):
        page = self.sender()
        self.setUrl(url)
        page.deleteLater()

class MainWindow(QMainWindow):
    def __init__(self, *args, **kwargs):
        super(MainWindow, self).__init__(*args, **kwargs)
        self.browser = QWebEngineView()
        page = WebEnginePage(self.browser)
        self.browser.setPage(page)
        self.browser.setUrl(QUrl("http://yandex.ru"))

When navigating through any site from Yandex search results, or simply when navigating a link with target="_blank" ... In the program, the page opens in the same window, but the counters see such a transition incorrectly without a referrer. Seems like a direct entry. Tested from my sites the same way .. If in a normal browser I go with target="_blank" then the referrer is visible to the transition and the site from which the transition was displayed is displayed. If I switch from the program with the code shown above, it goes as a direct entry. Help me to understand. Thank you!