If you right-click on the track, you should be able to separate the audio and video. That will allow you to adjust the timing. It may be as simple as sliding the entire audio track to the right by a couple of seconds.
Is this a live recording? We used to have the same problem when we first started out with the signal quality of our internet connection. The online training company suggested that some areas, especially business areas were less dense in the mornings than the afternoons. Our Facilitators knew to wait for the slides to change over and I would fix the problem on the edit