1. **Remove Screen Protector**: While you mentioned you have a good quality screen protector, sometimes certain screen protectors can interfere with the facial recognition technology. Try removing the screen protector temporarily to see if it improves recognition.
2. **Re-enroll Face**: Delete the existing facial recognition data and re-enroll your face. This ensures that the phone captures your face in various lighting conditions for better accuracy.
3. **Well-lit Environment**: Make sure you're in a well-lit environment when registering your face and when trying to unlock the phone. Adequate lighting helps the camera capture facial details more accurately.
4. **Clean the Camera Lens**: Ensure that the camera lens is clean and free of smudges or dirt. A dirty lens can affect the accuracy of facial recognition.
5. **Software Update**: Check for any available software updates for your Samsung Galaxy S23 Ultra. Manufacturers often release updates that can include improvements to facial recognition algorithms.
6. **Report to Samsung Support**: If the issue persists, consider reaching out to Samsung support for further assistance. There might be a specific issue with the hardware or software that requires their attention.
Regarding the comparison with your Samsung Galaxy A52s, it's worth noting that different models may use different hardware for facial recognition, which could account for the difference in performance.
Remember to be cautious when handling your phone, especially if you've removed the screen protector, to avoid any potential damage.
Kindly make sure that the phone is updated to the last software update, try to reset all the settings from the settings >General/ General management> Reset > Reset all settings. And, If you are using screen protector make sure to remove it. Otherwise, you should visit the service center.