Problem with mandibular plane in bone reconstruction planner

Hi! I’m new in 3slicer, i had only one case of mandibulectomy in 3 d slicer the past month.
Now I’have a problem when i do te positioning of mandibolar plane. Why when i set mandibular plane in correct position they cut off a piece of contralateral mandible ? So i can’t have a pre plating model to print with all the mandible .
For Example i had to do a recostruction of left ramus. When i set my 3 mandibular plane, the “prolong” the cut also in the right ramus, cutting condile and other pieces.

Hi

Please check this:

It should solve the problem

Mauro