Please refer to the following steps to resolve the issue:
1. If you notice lag or frequent buffering, switch the video quality to a lower setting. Set the video quality to [Auto] or select [360p smooth] mode in the Mi Home/Xiaomi Home APP for better performance, especially if your internet speed is not very high. This will reduce buffering and help the video load more smoothly;
2. If the audio and video are out of sync, it's caused by a slow or unstable network connection. Check the camera’s Wi-Fi signal strength and ensure it's connected to a stable and high-speed network;
3. Ensure that your phone is not overloaded with applications or tasks, as this can also contribute to lag or sync issues.