QTextCursor::movePosition(NextCharacter, MoveAnchor) does not move cursor if a text is selected

QTextCursor::movePosition(QTextCursor::NextCharacter, QTextCursor::MoveAnchor) does not move cursor position IF a text is selected. See the code snippet below. In the first cursor move, it keeps anchor and selects first three letters and places cursor after the third letter, i.e. position == 3. The next movePosition() call should move the cursor to the next letter, i.e. it is expected to have position == 4. But in fact the cursor remains after the third letter (position == 3) and the only effect is that the operation only cleared the previous selection. This is very unexpected behavior given what is written in the documentation.

#include <QApplication>
#include <QDebug>
#include <QTextEdit>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QTextEdit w;
    w.setPlainText("abcdef");
    QTextCursor tc = w.textCursor();
    tc.movePosition(QTextCursor::NextCharacter, QTextCursor::KeepAnchor, 3);
    qInfo() << tc.position() << tc.selectedText(); // prints: 3 "abc"
    tc.movePosition(QTextCursor::NextCharacter, QTextCursor::MoveAnchor);
    qInfo() << tc.position() << tc.selectedText(); // the cursor was not moved! prints: 3 ""
    w.setTextCursor(tc);
    w.show();
    return a.exec();
}

I understand there is a certain logic in what is happening. It seems that NextCharacter behaves the same as pressing right arrow key on keyboard. Because if there is a selection, then pressing the right key will clear the selection but not move the cursor. However documentation does not mention this and it gives the impression, that the the cursor should be moved regardless of the previous selection.