Roto Brush tool selects whole frame and skips frame
So Im trying to learn How to use the roto tool, if this is a obvious beginner misstand Then I am sorry But whats going on I am selecting the fore and background this goes fine but after around 1,5s of film suddenly the changes I make in adjusting the background/foreground only apply on the next frame. Is this normal behavior?
and the next thing which I think might be related is that when I use the tool on another layer but the same footage (duplicated) but at a later point in time it selects the whole frame with no way to edit.

