QLabel is not updated if QVideoWidget has source set and the QWindow has FramelessWindowHint set

When running a program that has QLabel and QVideoWidget visible at the same time, if the QVideoWidget has a source set and the QWidget they are shown in has a FramelessWindowHint set, updating the QLabel does nothing. Removing either the video source (QMediaPlayer) or the FramelessWindowHint fixes this issue and the label can again be updated properly. This bug is visual only, the text in the label is actually updated, but not shown to user. If the QMediaPlayer is playing something (i.e. a video), it does not affect the outcome of this behaviour.

Steps to reproduce:

• Run attached sample
• EXPECTED: Text in the QLabel updates once per second
• ACTUAL: Text does not update