difficult to say with only this informations. It depends on the values of operation and the kinematics settings in your post. Is the post created with a machine model or is it created without a kinematic model? What are the limits settings in the post in real machine kinematics properties? Do you change any other settings in the Tilting plane Kinematics or TCPM or use these properties the current kinematics values?
Sometimes i prefer the way to first unlimited the 4th and 5th axis to find the reason for it. From your information i would say vectors are correct. But not sure if e.g. the spindle direction is correct?
This is a machine which can not work if the tool axis vector component for Z (mom_tool_axis(2) is less than 0)
So please see in your operation if this happends.
In other words the plane can only have values from 0 to 90 degree.
Hope this helps