Hi Trachinusdragon,
Thanks for project! I spoke with developers about this and learned that only root component’s physics state is replicated. As such, physics results are not being replicated properly because your root is not simulating physics. To make this work in your test project, I bypassed Set Is Replicated for static mesh components and just used Set Simulate Physics for them on Begin Play. Then I took root mesh component and enabled Simulate Physics.
Now I’m not sure what you’re attempting to create here, but it seems like you want root static mesh to remain in place with no physics simulation, and components to react to physics. In that situation, it would be better to use two different Actor Blueprints, one for base that doesn’t react to physics, and other that does. You can then attach other to non-physics Actor, and they’ll each respond to physics as you expect.
To properly replicate change in position as a result of physics on both Server and Client, you’ll also need to make sure you’re doing all physics movement on Server. If Client is one changing behavior, you’ll need to use an RPC call to Server to have Server do it instead, because replication in UE4 runs from Server to Client, and not in reverse.
Hope that helps! Let me know if any of that wasn’t clear or you need any further assistance.