I have been having the same problem. Everything we stream live, when playing back the recording of it the audio lags behind the video. And today while testing, the audio actually was ahead of the video.
This very much seems to be a problem with the recording function at Livestream because the live stream plays fine. Support too has been asking us for system specs and bandwidth info. all of which report back fine. Bandwidth is not the issue. But I do not think Livestream support will take the time to work thru and solve the issue.