Mac OS: QWidget::setCursor for QCursor created from QPixmap does not work second time

STEPS:
1. Create project with any QWidget and resources containing at least 2 PNG files (see attachment)
2. Create QPixmap from one of PNG
3. Create cursor from QPixmap (left default hotspot)
4. Call setCursor for the widget
[OK]
5. Create QPixmap from another PNG
6. Go to steps 3, 4
[BUG_1]
Cursor wasn't changed

Investigation:
Same for overriden QApplication's cursors.
Same if call QWidget::unsetCursor() before step 4.
Works OK if do same with predefined Qt cursors (shapes from enum)

[BUG_2]
The really clickable cursor's hotspot is (0,0) though QCursor::hotSpot() says that it is set to (width/2, height/2)