Could it be the computer is just not fast enough to keep up with real-time rendering? I find dynamic linking from CH to AE can be VERY slow on my weak laptop. It might come out right on the final render.
Otherwise check things like the frame rate (FPS) on CH and AE composition? (I doubt this is the problem, but only other thing I can think of. I suspect its the first problem.)
Personally I avoid dynamic linking because my computer struggles. I render a video file with alpha channels as much as possible in CH and load that file into AE, then use dynamic linking for short segments where it is worth the speed pain (e.g. trying to align things exactly between CH and AE). That is, I do use dynamic linking, I just to to minimize it.