I have a video with an interview-object that sits relatively still, but moves head sometimes. When tracking the mask in order to color correct the object and not the background, the automatic function doesn't track it at all. The mask is completely still, and doesn't move. There are keyframes there, but the mask itself is absolutely still. When moving towards different points and tracking forward from a different position, it tend to perform even worse tracking the object.
It shouldn't matter what type of mask you use: bezier etc.
Premiere will use whatever is inside the mask to track, so if you have a larger mask that contains some of the background as well as the head, then the mask might not move because it's trying to track the background. If you make your mask smaller so it only contains parts of the head/face then it should track correctly. Track first and then expand/feather.