Conda version QT gui black screen

Hi all:
recently I notice that geant4 has an version build base on Conda
I install it with

conda install geant4

on Mac OS X Big Sur
and then using exampleB2a it runs, but I cannot choose anything on the application.
The window seems exist but I cannot do anything

However if I build it by myself, It’s OK without any problems.

It seems I’ve the same warning message as
qt.qpa.window: <QNSWindow: 0x7f9c706c9570; contentView=<QNSView: 0x7f9c72608b10; QCocoaWindow(0x7f9c72608930, window=QWidgetWindow(0x7f9c72607c30, name=“QGLWidgetClassWindow”))>> has active key-value observers (KVO)! These will stop working now that the window is recreated, and will result in exceptions when the observers are removed. Break in QCocoaWindow::recreateWindowIfNeeded to debug.

Does anyone has the same problem with me?