To troubleshoot audio sync issues on a Smart TV, the following steps should be taken:

1. Check the HDMI cables for any signs of damage, and reconnect them firmly into the TV and any other devices.
2. Make sure all video software or apps are up-to-date.
3. If there are any additional audio settings on the TV, make sure they are correctly configured.
4. Ensure that the TV’s power supply is steady.
5. Set the TV’s audio output to Auto to ensure that any delay in audio is being accounted for.
6. Check that your soundbar (or other audio devices) settings are correct.