The PIE editor window becomes a little ‘jumpy’ (latency or fps dropping every few seconds) when an actor is attached this way, and I’m not sure why. Let me know if this is the correct way to add an actor to a character in multiplayer and save a variable as the actor on the character. The HeadItem variable is set to Replicated.
Edit: This tutorial explains how to make custom events run on server, multicast, and run on owning client: Networking Overview for Unreal Engine | Unreal Engine 5.1 Documentation