When I’m calling spawnActor from each playerController, shouldn’t there be two of them?
No, unless you spawn it on the server and it replicates, you will only get one 
Each client has their own world and runs their own simulation of it, and you use replication to sync them (as far as you need). That sync always happens through the server. Clients can only communicate with the server via RPC RunOnServer but not with each other, and the server can send things to clients via replication.
That means, that everything that should be known to all clients, needs to go through / happen on the server. If you spawn anything on a client (regardless whether that actor is marked replicated or not), the server and therefore the other clients will never know about.
Could you show your logic to rotate the character in the widget?