I found solution.
With PySide QWidget transparancy have bug with QGraphicWidget. If QGraphicWidget have parent widget with transparent background mouseClickEvent doens't work.
With PySide2 this bug is fixed.
For fix this problem with Pyside I use steelSheet and set background rgba to 1.0 and I hide background.
But with PySide2 transparency option is different and show background. But this trick is not util now.