Hi, @ISAPoliTO.
There's a difference between lip-sync issues and lag issues. Stream services almost always have some built-in lag time... so you will see the video on the live stream be somewhere between 5 and 15 seconds later than the live feed you see on Zoom.
Normally, there should not be any lip-sync issues... that is, the lips and sound should move together, as long as you are listening to the same audio source that you are watching video from. But some lip-sync will occur -- Zoom will often delay audio briefly if the speaker's Internet connection is slow or unreliable. And packets from Zoom to your streaming service might also be affected by a variety of Internet bandwidth issues.
I don't do a lot of Livestreaming, but the times I've done it, I've never had a noticeable lip-sync issue downstream of the Zoom feed that wasn't also apparent in the Zoom live view, meaning that the issue is more at the speaker's computer and out of our control.
I hope that helps!
