Resource pack editor bug

Hi i found a bug with the resource pack editor: when you toggle an arm, the head, a leg visibility to draw on hidden zones of a part (e.g the inside of an arm, the shoulder), what you are drawing on the toggled part doesn’t appear on the right side (if i draw on the toggled-visible body the line appears on the hat surface, if i draw close to it, or maybe on the arms if im drawing on the inside-shoulders). Please fix it, the resource pack creator is awesome! (sorry for the bad english)