QCalendarWidget keyboard input to change date completely messed up

Focusing a QCalendarWidget and trying to input a date with keyboard in any format seems to result in very curious date selection. The date selection does not match the input at all in Qt 5.14.2. In contrast in Qt 5.12 it seems to work mostly fine but inputting day and month starting with 0 would result in an similar issue.

Steps to reproduce the issue:

1. Run the Qt example calendarwidget (https://doc.qt.io/qt-5/qtwidgets-widgets-calendarwidget-example.html)
2. Click on the calendar to focus
3. Attempt to type any date with keyboard and watch the grey rectangle displaying the input date.