QDateTimeEdit handles DST changes incorrectly

Please run the attached code and try to change the hours to 3.00 either using the arrow or the up key.
The QDateTimeEdit becomes empty and it logs:

QLineEdit::setSelection: Invalid start position (11)

Other issue:

1. set the hour to 4, (same date) lower the time to 3.
2. Now the "down" spinner gets disabled.

Result: it's not possible to jump from hour 3 to hour 1

Other issue:

1. set the date to 27/oct/2019
2. set the hour to 1
3. advance the hour

Result: hour 2 is only shown once (without any indicator for DST/standard
time)