“cv2.VideoCapture()” does not work properly on Monterey

cap_device = 0						# built-in camera of MacBook Pro 2018
cap = cv2.VideoCapture(cap_device)	
cfps = int(cap.get(cv2.CAP_PROP_FPS))

The program above can’t import video properly from built-in camera of MacBook Pro 2018. In my case, cfps(in the above program) is 5Hz and import frequency also behaves about 5Hz.

How can I solve this problem? Or is it a bug?