Server Version#: 1.41.3.9276
Player Version#: 7.28.7.9683
I recently replaced my Vizio E60-C3 with an LG C3 and have started experiencing slight lip sync issues in Plex. My setup includes a Roku Ultra (Model 4660X2, 2018) connected through a Marantz NR1403 receiver. I’m aware that I won’t get 4K passthrough with this setup, and that’s fine for now.
What’s Happening:
Since installing the LG C3, most videos in Plex have a minor but noticeable lip sync issue. This doesn’t happen with all content, but it affects the majority of what I’ve tested. Importantly, this issue only appears in Plex—Netflix, Amazon Prime, and other Roku channels are all in sync. The problem only started after I switched to the LG C3.
Additional Testing:
- On another TV (with an Apple TV 4K), the exact same Plex videos show no lip sync issues.
- I tried connecting the Apple TV 4K through the Marantz NR1403, which worked last year, but it eventually stopped working with the old Vizio as well and now I’m unable to get a signal with the new LG C3 either.
- Connecting the Apple TV 4K directly to the LG C3 shows no lip sync issues in Plex.
- Connecting the Roku directly to the LG C3 still results in a slight lip sync problem, although it’s not as bad as when going through the Marantz.
- Using the Roku with the older TV showed no lip sync problems at all.
Troubleshooting Steps Taken:
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Roku Log.txt (183.9 KB)
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Disabled Direct Play and toggled Allow Direct Stream off. Disabling Direct Play helped a bit, but disabling Direct Stream had no effect.
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Followed a Reddit suggestion to adjust LG C3 picture modes (SDR, HDR, DV) with Real Cinema ON and TrueMotion OFF, as well as enabling “Match screen and sound > bypass (ON)” under sound settings. These changes had no positive effect on the issue.
Request for Help:
Has anyone experienced similar lip sync issues after changing their TV when using Plex on a Roku Ultra? Any suggestions on further troubleshooting steps or settings adjustments would be greatly appreciated.
