For your reference, here are some troubleshooting steps:
1. Reboot the device to see if it’s back to normal. Sometimes a simple reboot can solve the problem;
2. Check whether it is caused by the low reading rate of the memory card;
3. If possible, please replace the memory card. It is recommended to use a well-known brand and qualified memory card to ensure the normal operation of the camera.
4. When the picture is not synchronized with the sound, check if the camera's network connection is working properly. If the delay is too much, try exiting the video and entering again;
5. When the video lags or shows the loading sign frequently, switch the clarity of the video to Auto or Smooth mode.
We hope the above methods can help you solve the problem. If your problem still exists, please contact the local after-sales service center for further assistance.