Audio drifting out of sync with the picture on a Firestick has two genuinely different causes, and the fix for one does nothing for the other. Working out whether the problem happens on specific IPTV channels only, or on absolutely everything you watch, tells you which one you have.
Drift on some IPTV channels only
If sync issues appear on certain live channels but not others, and not on Netflix, Prime Video or other apps, the cause usually sits at the app or stream level rather than the Firestick itself. Switching the IPTV app’s internal video player (many apps such as TiviMate let you choose between an internal and an external player), or trying a different app entirely with the same login, resolves this in most cases — it points to how that specific stream is being decoded, not a fault with your hardware.
Drift on everything you watch, not just IPTV
If audio lags behind picture on all content — Netflix, Prime Video, live TV, everything — the cause is more likely a device-wide audio setting rather than anything app-specific. A known culprit on Fire TV devices is Dolby Digital or Dolby Digital Plus passthrough to certain AV receivers or soundbars, which some users report causing a small but constant delay across all content. The fix is to go to Settings, Display & Sounds, Audio and turn passthrough off, forcing the Firestick to decode audio itself rather than passing it through unprocessed. Be aware this can make surround sound feel slightly flatter on some systems — it is a genuine trade-off, not a free fix, but it resolves the sync issue for many people it affects.
Quick checks before changing settings
Before changing any audio settings, try a different HDMI cable and, if you can, plug the Firestick directly into the TV rather than through a soundbar or AV receiver temporarily, to see whether the delay is introduced further down the chain rather than by the Firestick itself.
Frequently asked questions
Why is the audio out of sync on only some IPTV channels?
This is usually stream or app-specific rather than a Firestick fault. Try switching the app’s internal player setting, or test the same channel in a different app.
Why is my audio delayed on everything I watch, not just IPTV?
Check whether Dolby Digital or Dolby Digital Plus passthrough is enabled under Settings, Display & Sounds, Audio — disabling it fixes this for many people, though it can slightly change how surround sound sounds on some systems.
Will turning off Dolby passthrough make my sound worse?
It can make surround sound feel less full on some AV setups, since the Firestick decodes the audio itself rather than passing it through unprocessed. It is worth testing to see whether the sync improvement is worth that trade-off for you.
Could a bad HDMI cable cause audio sync problems?
It is possible, particularly with a cheap or damaged cable. Testing a different cable and a direct connection to the TV is a useful first check before changing any settings.