actual real-time playback? What a concept!

One other note: we've considered having a way to make rehearsal mode more explicit because it is a source of confusion, especially for those expecting traditional frame by frame animation behavior. We just haven't found a design we like to make it obvious without being more annoying to do things in the way Character Animator was designed to work.

There's two parts that might explain the discrepancies you describe here.

The first one is that when the time needle is at a point in time and not playing, it is in what we call "rehearsal mode". Any armed (the red dots) behavior or behavior parameter will be taking values from live input, not the recorded content at that point in time, so what you see (until you press play) is a mix of recorded content for unarmed behaviors/params at that point in time and live inputs. The built in "Recording Lessons" tutorials (available in the help menu) has a couple of chapters that touch on this a bit. It can be confusing at first, but Character Animator is not a traditional frame by frame animation program.

The second explanation is trickier. If you have certain behaviors like Cycle Layers or Physics, there are some aspects of behavior that might not be exactly accurate unless you play from time zero (because the precise results of what "should" be showing at frame N is the sum of all the things that happened in frame 0 to N - 1) The fact that pressing Play sounds like it shows what you intend makes me think the first explanation is the important one, but for the sake of thoroughness, I wanted to also note this second possibility.

The second item could be improved with better caching, but perfect results can only be achieved by processing from time 0 onward, so if we made that a hard requirement, making a small change to a parameter at the beginning and then quickly jumping to the end could (in the worst case) take almost as long as rendering the entire timeline. Since most results are pretty close with less run-up than that, we chose to not take that hit and accept that it may mean results are not exactly right 100% of the time.

Hope that helps.
Dan Tull

P.S. I won't lie to you. Ever. Do not presume that I will.

This sounds like a bug to me. Can you provide steps using our template puppets that explain what you are expecting and what you are actually seeing? I was able to find this section of a tutorial that shows playback and scrubbing in a complex scene. How does this compare to what you are seeing? https://www.youtube.com/watch?v=VhCKD5vl848&t=1110s