macOS: QtWidgets.QTextEdit.append() does not repaint the widget in pyside2

When I use QtWidgets.QTextEdit.append() in pyside2, the widget gets not repainted and the appended text is invisible. The appended text becomes visible again when e.g. selecting all text in the edit pane.

When creating the exact same code in C++, all works as expected. To demonstrate the issue, I've created a project in C++ and Python, using the same mainwindow.ui file from the QtDesigner. The git repo can be found here:

https://github.com/gilbertfrancois/qt-app-template

Attached is a video to demonstrate the issue.