Sentinel +switch-master announcement missed if master dies while connected

I'm testing Redis, StackExchange.Redis, and Redis-Sentinel in order to setup a appropriate HA environment.

I've noticed that when i stand up a sentinel cluster as described in these docs: https://hub.docker.com/r/bitnami/redis-sentinel/ and i shutdown the master after a multiplexer connection has been successfully established by a client using StackExchange.Redis. The multiplexer fails to realize that the failover has occurred and continues to queue messages for the now non-existent leader.

Funny thing is If i manually trigger a failover using the sentinel-cli with SENTINEL FAILOVER mymaster the multiplexer realizes the change and appropriately updates the leader.

I looked into the code and noticed that the +switch-master subscription hook is never fired when the primary Redis is shutdown even if the sentinel associated is still up and running. In the situation where i manually trigger the failover, the hook properly fires.

https://github.com/StackExchange/StackExchange.Redis/blob/f6171a19a0be078c6528b4631d42dfa4adcc8564/src/StackExchange.Redis/ConnectionMultiplexer.Sentinel.cs#L33-L62

I've confirmed that the sentinel is still issuing the +switch-master command in both scenarios.

I've tried multiple ways to setup the multiplexer, here is my last iteration.

var opts = new ConfigurationOptions
            {
                SyncTimeout = 60000,
                AbortOnConnectFail = false,
                Ssl = false,
                Password = config.Password,
                ReconnectRetryPolicy = new LinearRetry(2000),
                ConnectRetry = 30,
                ServiceName = "mymaster",
                ConfigCheckSeconds = 10
            };
            opts.EndPoints.Add("redis-sentinel-1", 26379);
            opts.EndPoints.Add("redis-sentinel-2", 26379);
            opts.EndPoints.Add("redis-sentinel-3", 26379);

            var log = new LoggerWriter(_log, LogLevel.Information);

            //_multiplexer = await ConnectionMultiplexer.ConnectAsync(opts, log);
            _multiplexerSentinel = await ConnectionMultiplexer.SentinelConnectAsync(opts, log);
            _multiplexer = _multiplexerSentinel.GetSentinelMasterConnection(opts, log);


            _multiplexerSentinel.ConfigurationChanged += (s, e) =>
            {
                _log.LogError($"Sentinel configuration changed (Sentinel): {e.EndPoint}");
                _log.LogInformation($"New server status: {_multiplexerSentinel.GetStatus()}");
            };
            _multiplexerSentinel.ConnectionFailed += (s, e) =>
            {
                _log.LogError($"Connection failed (Sentinel): {e.ConnectionType}, {e.FailureType}, {e.EndPoint}, {e.Exception}");
                _log.LogInformation($"New server status: {_multiplexerSentinel.GetStatus()}");
            };
            _multiplexerSentinel.ConnectionRestored += (s, e) =>
            {
                _log.LogError($"Connection restored (Sentinel): {e.ConnectionType}, {e.FailureType}, {e.EndPoint}, {e.Exception}");
                _log.LogInformation($"New server status: {_multiplexerSentinel.GetStatus()}");
            };
            _multiplexerSentinel.ConfigurationChangedBroadcast += (s, e) =>
            {
                _log.LogError($"Connection changed via broadcast (Sentinel): {e.EndPoint}");
                _log.LogInformation($"New server status: {_multiplexerSentinel.GetStatus()}");
            };

            _multiplexer.ConfigurationChanged += (s, e) =>
            {
                _log.LogError($"Configuration changed: {e.EndPoint}");
                _log.LogInformation($"New server status: {_multiplexer.GetStatus()}");
                //var info = _multiplexer.GetServers().Where(x => x.IsConnected).Select(x => x.InfoRaw()).ToArray();
               // _multiplexer.Configure(new LoggerWriter(_log, LogLevel.Information));
                //_log.LogInformation($"Server info: {info}");
                // _multiplexer.PublishReconfigure();
            };
            _multiplexer.ConnectionFailed += (s, e) =>
            {
                _log.LogError($"Connection failed: {e.ConnectionType}, {e.FailureType}, {e.EndPoint}, {e.Exception}");
                _log.LogInformation($"New server status: {_multiplexer.GetStatus()}");
            };
            _multiplexer.ConnectionRestored += (s, e) =>
            {
                _log.LogError($"Connection restored: {e.ConnectionType}, {e.FailureType}, {e.EndPoint}, {e.Exception}");
                _log.LogInformation($"New server status: {_multiplexer.GetStatus()}");
            };
            _multiplexer.ConfigurationChangedBroadcast += (s, e) =>
            {
                _log.LogError($"Connection changed via broadcast: {e.EndPoint}");
                _log.LogInformation($"New server status: {_multiplexer.GetStatus()}");
            };

Start in src/StackExchange.Redis/ConnectionMultiplexer.Sentinel.cs around the linked lines and reproduce the two failover paths described: shutting down the master and issuing SENTINEL FAILOVER mymaster. Trace why +switch-master is handled in one case but not the other; done means the multiplexer detects the shutdown-driven failover and updates the leader instead of queueing messages for the old master.