I tried to create a new Multi-camera sequence by selecting my clips and leaving everything on auto except for the synchronize point which I set to "Audio" and "Track Channel" to track 1( I also tried synchronizing by Clip Marker and In points).
It synchronized and created the multi-cam sequence but when I dragged it into my timeline only the audio came with it. If I double-clicked on the sequence to open it in the Source monitor it displayed properly with both audio and video.
If I manually synchronize the video in the timeline and then nest them and create a multi-cam sequence from that nest, the video appears and I can cut between cameras but the audio doesn't appear. If I open my nest sequence it is in there but not in my main timeline.
Specs for the computer I am currently on, it happens on my iMac as well:
2.3 GHz i7
GeForce GT 750M 2GB