How could I stop my character from behaving weirdly when I attach a springconstraint to the right arm?

[ColdFoxy07 (ColdFoxy)]

Hey there! I’m making a grapple system, and I want to have a rope constraint attached to the right arm of the character, but whenever I do this it doesn’t behave how it would if I attach it to the RootPart.

Video:
https://streamable.com/52g8ym

Script (local):

local targetPosition = mouse.Hit.Position
		
attachment0 = Instance.new("Attachment", character["Right Arm"])
attachment1 = Instance.new("Attachment", mouse.Target)
attachment1.WorldPosition = humanoid.RootPart.Position
visualSpring = Instance.new("SpringConstraint", humanoid.RootPart)
visualSpring.Attachment0 = attachment0
visualSpring.Attachment1 = attachment1
visualSpring.Color = BrickColor.new("Really black")
visualSpring.Visible = true

local startTime = tick()

updateConnection = game:GetService("RunService").RenderStepped:Connect(function()
	local elapsed = tick() - startTime
	local progress = elapsed / timeToReach
	if progress >= 1 then
		progress = 1
		updateConnection:Disconnect()
	end
	attachment1.WorldPosition = humanoid.RootPart.Position:Lerp(targetPosition, progress)
	visualSpring.Coils = 3 * (1 - progress) 
end)

How would I fix this? Any help is appreciated!

[ColdFoxy07 (ColdFoxy)]

I fixed it by just making a fake part and attaching to the right arm by updating it’s CFrame every frame.