In many cases the issue is not the sound, it’s the resolution setting. It may not make sense but try it. On the Roku device home menu, go to settings and then “Display type”. Check the 720p resolution setting. Go back to home. Now Go to your program and check the synchronization. There are reasons for this that would take a little time to explain. In short, it’s faster/easier for the Roku express and other models to process lower resolution this maintains audio and picture synchronization. Bandwidth from your provider can be an issue as well or your cable connections, older tv, etc. just try the lower resolution and see if that takes care of the lag between Video and audio. Good luck.
I am having the same issue as my equipment was professionally installed by Best Buy Magnolia department. There is a audio/ video sync issue when watching Amazon Prime through the Roku Ultra so freakin frustrating and I have rebooted the Roku Ultra, cleared the cache, turn the leveling to "off" and still no change. Have an excellent internet connection. What to do now thinking 🤔about? Thinking about dumping the Roku Ultra and getting a Amazon Cube to stream, any thoughts?
As far as I can tell, pretty much ALL brands of streaming devices exhibit this out-of-sync problem for at least *some* people. Probable exceptions: PCs, MACs, most tablets and smartphones, and probably Comcast Xfinity’s FLEX devices - all of these have far more robust hardware and software capabilities to help automatically correct for such problems “in real time” (“on the fly”) and of course accordingly have far higher price tags (the FLEX devices may be offered on loan and at no additional charge to Xfinity Internet customers but that doesn’t mean they are cheaply made or inexpensive to purchase such as Rokus and the like).
It may very well be more a function of media server and/or other internet data transmission or WAN issues rather than the devices themselves, or at least a *combination* of device and non-device issues that produces this particular problem.
I'll say it again: This problem started a couple of months ago when the software was updated to version 9.4.0. Before that I never noticed sync issues. Others have reported the same thing, and it happens on the most basic devices as well as the newest most advanced ones, so it seems to be a software issue. I reported it to Roku more than a month ago. They just don't care.
On my system, some programs are WAY out of sync, especially Amazon Prime. Selected programs on Roku Channel were in sync before the update but are way out of sync now. Other programs are nearly in sync (close enough), none seem to be perfect. Movies on TCM or Criterion are hit or miss. Before the update they were perfectly in sync, now most are off by a few frames. Perhaps if you haven't had the problem, it could be the type of programing you are watching, the type of audio system you have, or just luck.
nv1: Nope. I currently have 9.4.0 (build 4200-46) on my Ultra (model 4660X). I USED to have a/v sync issues on a few “channels” but no longer. So OBVIOUSLY it is not simply a matter of just the 9.4.0 version of Roku’s OS.