Top Down Movement Help

Hello, I’m trying to make a top down system, but the movement breaks when pointing the mouse directly about the character.

Video:
https://vimeo.com/manage/videos/1000527692/privacy

Script:

-- mousePos is mouse.Hit
part.CFrame = CFrame.lookAt(part.Position, Vector3.new(mousePos.X, part.Position.Y, mousePos.Z))
	
if moving then
	part.AssemblyLinearVelocity = boat.PrimaryPart.CFrame.LookVector * 20
else
	part.AssemblyLinearVelocity = Vector3.new(0, 0, 0)
end

Thank you.