Preview not moving to new zero point

Always prior to this when I would rezero an axis the path preview would snap to that new position for each change. Lately I have noticed that it randomly seems to not do this. I have to reload the file to get the preview to locate properly to new relative zero positions. Has anyone else run into that? A bug or something else. It doesn't seem to affect the actual machine movement, just the preview toolpath displayed on screen.

Ignore this (as you already have) - This issue is encountered when I use pyVCP or other HAL components to set the zero via MDI. The GUI doesn't know that it happened. Now that I use the control panel or pendant almost exclusively I realized the issue. I wasn't using the "Touch Off" buttons in Axis anymore. When you use those, the preview pops to the new location immediately.