I’m not sure where this code is located, so I’m not sure if you should pull “Get Player Character”, or what. But you need to use either “Attach Actor To Actor” or “Attach Component to Actor” with “Keep World” as the setting, I think. You may want to play around with that setting, sometimes it can give really subtle differences. But it’s going to be “Player Character” and Spike for “actor to actor” and Player character->cast to BP_ThirdPC->get Skeletal Mesh->attach for “Component to Actor”.
Hope this helps! 