Modulating the occupant's Position

When we Try to Modulating the Position while its occupied, it doesn't make an update after saving, and the pervious Position not had end date, and we found the system create a new Position for new changes, in same time we found the employee has end date from the pervious Position.

we want to make this change while the position occupied without end the employee has end date with this Position, and the Position has date track of this change.

We want to know if that's possible or no?