The problem with confidence (certainty) for all detected hand points returning as 0.0 can be due to several possible causes. Here are some steps you can try to fix the problem:
Incorrect use of parameters
Alternative parameters
With mp_hands.Hands(static_image_mode=False, max_num_hands=2, min_detection_confidence=0.5, min_tracking_confidence=0.5) as hands:
Update/check MediaPipe version
Make sure the camera or video is of good quality
Debug the results
if hand_results.multi_hand_landmarks: For hand_landmarks in hand_results.multi_hand_landmarks: print(hand_landmarks)