Solving playback issues

[Brando_70]

I have the new Ultra, LG OLED with HDMI arc set to passthrough, and a new Vizio soundbar. No matter if I use the Roku app's built in audio delay correction, or the av sync adjustment on my soundbar, after a few hours of playing content the audio and video get out of sync. 

This happens with all apps, with the built in tv speakers or soundbar. The only fix I've discovered is redo the Roku app's delay correction or a reboot of the Ultra.

I've tried factory reset, but the issue still eventually shows up. I have a streaming stick 4k that does not have this issue, and I think it could be related to it Not having the Dolby ms12 encoder/decoder system like the 4850x Ultra. Another product with this same exact issue is the new Google TV Streamer, and it has the same Dolby ms12 system. 

I love the Ultra itself, but I can't be using a product that requires the customer to do something just to get it working as advertised. 

[RokuJohnB]

Hey @Brando_70,

Greetings from the Roku Community!

If you notice an A/V sync error when using your Streambar or soundbar with your TV and/or connected devices (e.g., game console, Blu-ray player, cable/satellite set-top box), read through the questions below to help narrow the problem.

1. Are all titles on a channel or device affected?
   When you encounter an A/V sync error, stop the playback of the movie or TV show and try a different title. Try another title on the same game console if you are playing a video game with an A/V sync error. If you determine that the sync error is isolated to a single title, the movie, TV show, or video game is likely poorly authored or damaged. Try watching the movie or TV show on another channel with streaming content or content from your cable/satellite provider. With physical media, try cleaning the disc or replacing it with an alternate copy.
   
   If the A/V sync error affects multiple titles, continue to the next step.

2. Are all devices affected?
   If multiple titles are affected, switch your TV to a different device (from the one where the A/V sync error was discovered) and play a movie, TV show, or video game on the new device. If you discover that the sync error only occurs on the original device, try restarting that device.
   
   If the A/V sync error occurs with multiple titles on a single streaming channel, close the channel and try watching content on another streaming channel. If the A/V sync error disappears, re-launch the original streaming channel and resume playback of the duplicate titles to determine if the sync error was an isolated event. Contact the service provider to report the issue if multiple titles are still affected only on one streaming channel.
   
   If the A/V sync error affects all devices, continue to the next step.

3. Try adjusting TV settings.
   To help fix an A/V sync error, try adjusting the TV settings described below. For detailed instructions, consult the online documentation for your TV model or contact the manufacturer directly.
   
   
   • • Some TV models have an A/V Sync feature that can often be found in an Audio sub-menu within the Settings menu on your TV. If the feature exists on your TV, try adjusting it to see if A/V sync improves. The feature may also be called something like Audio delay or Lip-sync.
     • Use the following suggestion if the sound is distinctly heard before seeing the picture.
       • Turn off advanced video processing on your TV, such as motion smoothing or noise reduction. These controls are often found in a Video or Picture Settings sub-menu within the Settings menu on your TV.
     • Try the suggestions below if the sound is distinctly heard after seeing the picture.
       • Set your TV's digital audio output to PCM. You can often find this setting in an Audio sub-menu within the Settings menu on your TV.
       • Try turning off Game Mode if the setting exists on your TV.

Please try doing this and see if it helps with what you're experiencing.

Cheers,
The Roku Community Team

[Brando_70]

@RokuJohnB Thanks for the reply. I've literally tried everything you've listed. As I'm typing I've just had to reboot the 4850x Ultra because after watching a 2.5hr video in the background, the audio and video went out of sync.

To directly answer your points:

This issue occurs on all apps.

I've done a total factory reset. 

I've switched HDMI ports and also changed HDMI cables. 

I've tried AV sync settings on my TV, including switching to PCM output. 

[ex5tube]

I have a Roku Ultra, and starting about 2 months ago (Feb 2025), I started having intermittent audio sync issues.

Sometimes I can momentarily toggle my TV input to my cable box, then back to the Roku Ultra, but other times I have to reset the Roku Ultra, to resolve the audio sync issues. I have an older Toshiba smart TV, and I have reset this TV to its factory condition, but I'm still having the issues. 

The audio sync issues occur on all apps that I use on my Roku Ultra (YouTube, prime video, Paramount+, etc)

What has changed in 2025, to start causing these intermittent audio sync issues?

[Brando_70]

So new update:  

After chatting with support, and getting the standard copy and paste support answers, they decided to send me a new unit at no cost. That's great service and I'm so appreciative.

But what's weird is my original 4850x unit had OS 14.5(current retail is 14.1). My new replacement mostly works with HDMI 2.0 auto lip sync, and the Roku app's built-in audio delay correction, works flawlessly, and gets in perfect sync. 

However, in any app, any situation, after 1.5-2 hours of play video of any kind, the perfect lip sync achieved by the Roku app goes away, and then the audio goes back to trailing video.

The solution I've found is backing out of the video that's been playing long to cause the audio delay to return, and going back into the same video or any other app's video OR just a restart of the unit.  I'm not sure what kind of issue would cause this, but I'm here for any support agents if you need further info.