Since that is your goal try doing this instead
UVictoryCharMoveComp* CustomCharMovementComp = Cast<UVictoryCharMoveComp>(CharacterMovement);
if(CustomCharMovementComp)
{
CustomCharMovementComp->CallFunction();
}
I have updated my wiki tutorial here:
https://wiki.unrealengine.com/Custom_Character_Movement_Component
Rama