Question about the boss device

What would be the way to trigger the device when a cinematic device stops?
This is what I have… What am I doing wrong?

using { /Fortnite.com/Devices }
using { /Verse.org/Simulation }
using { /UnrealEngine.com/Temporary/Diagnostics }
using { /Fortnite.com/Characters }
using { /UnrealEngine.com/Temporary/SpatialMath }
using { /Fortnite.com/Playspaces }

BossDevice := class(creative_device):

PlayerChar : ?agent = false

@editable
Bossprop : creative_prop = creative_prop{}

@editable
CinematicDevice : cinematic_sequence_device = cinematic_sequence_device{}


ProptranslationAxis : vector3 = vector3:
    X := 0.0
    Y := 0.0
    Z := -1.0


OnBegin<override>()<suspends>:void=
     CinematicDevice.StoppedEvent.Subscribe


OnStoppedEvent(Agent: agent):void =
    spawn{FollowPlayer()}
    

FollowPlayer()<suspends>:void = 
    
    loop:
        Sleep(0.01)
        if (PlayerList := GetPlayspace().GetPlayers(), FortCharacter := PlayerList[0].GetFortCharacter[]):
            Playerpostion : vector3 = FortCharacter.GetTransform().Translation
            Proptranslation : vector3 = Bossprop.GetTransform().Translation

            VectorToPlayer : vector3 = Playerpostion - Proptranslation

            RadiansVectorToPlayer: float = ArcTan(VectorToPlayer.X, VectorToPlayer.Y) - (PiFloat / 2.0)

            NewRotation : rotation =MakeRotation(axis := ProptranslationAxis, AngleRadians := RadiansVectorToPlayer)

            Bossprop.MoveTo(Playerpostion, NewRotation, 1.0)

        else:
             brea