Not authorized on test to execute command
Turns out that I was missing a /authDBName in my connection string. It should be this:
mongodb://myUser:userPW@SG-staging-111.servers.mongodirector.com:27017,SG-staging-43334.servers.mongodirector.com:27017/stagingDB?replicaSet=RS-staging-0&amp;ssl=true&amp;authSource=stagingDB