Thanks Chris! You are correct that adding the replication to the shield variable fixes the issue in this standalone project. However, I am also performing this variable replication in my main project. 
Good news is that it dawned on me what the problem was once I added the missing replication code. 
I am actually performing the replication on this “AActorShield” in my main project. BUT, I also am setting the mesh variable to replicated in my tags which is where the root of my problem is coming from! So if you set both the character’s shield to replicated AND set the shield’s “mesh” component to replicated then you will see this same behavior again.
This is where I figured I was having some sort of misconception about how the replication functionality of UE4 works. Why is this the case? I’ll update the project with these details once I get some time to do so later today.