Hey Axxi,
What I’d recommend is adding a Switch Has Authority after your Spawner’s Event Begin Play and connect the Authority pin to the SpawnActor node. That way you’re only spawning the light actor on the server. That ceiling light blueprint is set to replicate, so once you spawn it on the server it should replicate to the client. However, since it’s simulating physics, the movement of the actor will not replicate identically.
Let me know if you have any further questions, or if I’m misunderstanding your issue.
Have a great day