SPLINE LINES NOT MOVES ACCORDINGLY TO SPLINE HANDLES

Hi,

I'm looking for solutions on how to move spline lines accordingly with spline handles as such in the youtube, duration @ 5.12.
 

Currently mine is like this...
The spline lines graphical movement only moves when click on spline handle is released. Also spline handle cannot drag its length, only degree I able to.
I'm looking solution for spline lines continuosly moving when dragging spline handle.

 

ANy helps will be much appreciated. Thanks

 

https://www.youtube.com/watch?v=_TT897R1wp8&t=1918s