I apologize ahead of time if this is a known issue - I did a few searches to try and find a reference to this, but with no results.
The Shake action of ScrollTo does not work with CustomMovement.
Steps to reproduce:
1) Start a new project snd select the Example: Custom movement (asteroids) template
2) Add ScrollTo behavior to the Ship Sprite
3) Add Player->Shake to the existing On Space pressed event
4) Run game
5) Press space and NO SHAKE OCCURS
Its very odd...