I think I am having a similar problem. Either the image freezes and audio keeps going, or I get a black clicker effect before the entire sequence goes black and audio keeps playing. Another site suggested this happens because of chrome and if you have it open it will do this. You have to go in and change: System Preferences> System> Use Hardware Acceleration When Available.
This did not work for me but has helped several people. I have found that if I restart Adobe I will lose the last few edits I made but the flicker is gone. After that I can edit and add fxs no problem, until I add any title that has movement and the problem happens again. If I save all and reload I can see every thing fine but the problem instantly returns if that title is still in the sequence. Just audio. I tried rendering and exporting and I just get a green video with audio.