Causes:
1. The video file is incompatible with the video app or corrupted.
2. The internet connection is slow when streaming online video.
3. The video app is malfunctioning or outdated.
4. The Bluetooth earphones or speakers have some audio lag due to the wireless connection.
Solutions:
1. Re-download the video file and play it again.
2. Connect to fast and stable internet to try again.
3. Switch to another video app and check if the problem persists.
4. Unpair the Bluetooth devices and play the video again. If the sound delay is severe, you can try to reduce the distance between your phone and the Bluetooth device, pair them again, or use a wired connection instead.
If the above methods do not solve your problem, please back up your data in advance and go to the nearest realme Service Center with your purchase certificate for testing.