Bug when using refine edge tool

There’s a bug whenever using the refine edge tool in conjunction with the object matte tool. When masking multiple people, I am having the issue of after several frames, the entire subject will fade out completely. It seems that the AI is having trouble identifying new edges when the subject moves. Two screenshots are included below. The first screenshot is a frame about halfway through the scene. You can see where the black (refine edge tool) is trying to follow her hair (not doing a great job). The second screenshot shows the next frame when it bugged out, just masking both of the other kids. The kids faces are covered for safety reasons. 

The other problem is, when I unfreeze the object matte tool and try to fix it with one of the other tools, it recognizes that I’m selecting them, but then reverts back to bluring them out. I end up having to cut the section out and redo the object matte as a whole new mask on a different clip on the timeline.