Global change not working for baseline programme

I am aware of the need to change the planned start and planned finish of a baseline programme before attaching it to the programme that I am usuing to demonstrate a delay.

However in certain instances the planned dates are not being changed. ie an activity in progress with and actual start of the 30 May 2018 and a finish of the 3 Dec 2018 after running the global change to set the planned dates gives a planned start of the 30 May 2018 but a finish of the 30 Nov 2018 and not the 3 Dec 2018.

I assume that the global change is:

Condition 1 activity complete. planned start=actual start planned finish=actual finish

Condtion 2 activity in progress. planned start=actual start planned finish=finish

Is this correct?