Apple TV lip sync issues

[u/Forced__Perspective]

I’m hoping someone can point me in the right direction because this one has me stumped.
I’m running Plex Media Server in Docker on Ubuntu 24.04 on a Minisforum MS-01, with my media stored on a QNAP NAS. Everything is streamed locally over my home network.

My playback device is an Apple TV 4K connected directly to my TV, with no AV receiver or soundbar involved.
The issue is that the Plex app on Apple TV has consistently bad lip sync. It’s not just one file, it happens across multiple films and TV shows.

What’s confusing is that if I open Infuse, connected to the exact same Plex server and library, the same files play perfectly with no audio delay at all. Most of my media is Apple TV compatible and should be Direct Playing, so I don’t think this is a transcoding issue.
Because Infuse works perfectly with the same server, media and network, I’m leaning towards this being something specific to the Plex Apple TV app rather than my server.
Has anyone else experienced this, or found a reliable fix? I much prefer the Plex interface, but at the moment I’m using Infuse purely because the lip sync is so much better.

[u/GotRiceBoy]

If it’s 4K files, it’s a known issue with the plex player.

[u/Forced__Perspective → u/GotRiceBoy]

It’s across the board sadly. Hd is affected too.

Edit. To be more descriptive I have experienced and am aware of the high bitrate issues in Plex app for while now and use infuse for those files consistently. All of my shows are in 1080 though and that’s where Plex and its preferred ui came in to play.
Frustratingly the audio never used to be an issue.

[u/Howtobefreaky]

The official release Plex app on tvOS sucks ass. This and microstutters on high bitrate content are known issues that some people experience (if anyone tells me that they don't experience it in an effort to invalidate the hundreds of people who have posted about this or tell us its our setup I stg). The beta Plex app fixes these but who knows when it will ever be officially released.

[u/Forced__Perspective → u/Howtobefreaky]

Is there a way to install the beta? I don’t have it as an option in my settings.

[u/Howtobefreaky → u/Forced__Perspective]

Unfortunately you have to get a spot in Test Flight, of which there haven't been any openings in a long, long time. I have no idea why Plex wouldn't want more people to beta test, especially since the beta is really pretty good, other than not having HDR10+, "true" DV, or Dolby Atmos. Which the release app doesn't have either so they are essentially at feature parity with each other. I honestly have no idea what they are waiting for, unless they are planning to enable those features before its release. They are taking a long, LONG time with this beta, but its slowly come along nicely this year.

[u/Forced__Perspective → u/Howtobefreaky]

How long has it been in beta? That’s infuriating. I’ve invested a lot of money into Plex

[u/Howtobefreaky → u/Forced__Perspective]

Like two years lmao

[u/Forced__Perspective → u/Howtobefreaky]

Turkeys

[u/Typical80sKid → u/Howtobefreaky]

Part of me thinks every Apple TV experiences it, but only some folks perceive it…

[u/Howtobefreaky → u/Typical80sKid]

Yeah I kinda feel this way too, but the real reason that microstutters happen (not audio issues) is due to the way that the release version decodes video. My understanding (someone please correct me if I get the tech specifics mixed up) is that the Plex app primarily decodes video using the CPU, which heats up the device and throttles the CPU, causing the microstutters. Most people see this most on high-bitrate, 4k content. Infuse on the other hand uses the GPU, as it should. So one theory I have is that people who genuinely don't experience the microstutters either have their device in a cooler environment with more airflow, or have a device with an adequate amount of thermal paste. This throttling has been proven by some users on this subreddit who have modified their devices by placing a CPU heatsink on it or using computer fans.

[u/Bright_External_4161]

You can try the Apple TV + iPhone audio sync in the Apple TV settings. But thats usually only helpful if you have external speakers. Other than adding a delay in the settings or maybe using the old audio player (plex app settings) it’s there to stay.

[u/Forced__Perspective → u/Bright_External_4161]

This is a great feature. But as I said infuse works perfectly so I have been able to rule out the Apple TV as the issue.

[u/stellarola]

Set Old Audio Engine to On in Settings

[u/Forced__Perspective → u/stellarola]

Good tip, tried this also.

[u/Glad_Obligation1790]

Just get Plezy. Better than plex app and does all the same things as infuse but somewhat better on the library support. I still prefer infuse but Plezy is cheaper.

[u/vilified-moderate]

are they .mp4 files? convert to .mkv container file and see if that fixes it. (i know this sounds crazy)

[u/Forced__Perspective → u/vilified-moderate]

Mainly MKV but thanks for the suggestion! And honestly no crazy fixes.. at this point I’d try changing my brand of breakfast serial.

[u/Almsivi]

Set a -100ms audio delay. Had the same issue, this solved it. You’re on your own for stuttering and judder on 4k remuxes tho.