Service Restart failure - replacing dead connections failure

Seeing an error from the SDK under this KV scenario: 

Operations: Continuous upserts and gets 

Change: Stop CB on nodes 2,3,4 , wait 5 secs and then restart them.

Cluster:

1. kv
2. kv,index,fts,n1ql 
3. kv,index,fts,n1ql
4. kv,index,fts,n1ql

Error: Seeing this error after stopping the nodes

fail: Couchbase.Core.IO.Connections.DataFlow.DataFlowConnectionPool[0]

      Error replacing dead connections for 10.112.194.102:11210.

System.IO.IOException: The operation is not allowed on non-connected sockets.

   at System.Net.Sockets.NetworkStream..ctor(Socket socket, FileAccess access, Boolean ownsSocket)

   at Couchbase.Core.IO.Connections.MultiplexingConnection..ctor(Socket socket, ILogger`1 logger) in /Users/willbroadbelt/Documents/repos/couchbase/couchbase-net-client/src/Couchbase/Core/IO/Connections/MultiplexingConnection.cs:line 37

   at Couchbase.Core.IO.Connections.ConnectionFactory.CreateAndConnectAsync(IPEndPoint endPoint, CancellationToken cancellationToken) in /Users/willbroadbelt/Documents/repos/couchbase/couchbase-net-client/src/Couchbase/Core/IO/Connections/ConnectionFactory.cs:line 72

   at Couchbase.Core.IO.Connections.ConnectionPoolBase.CreateConnectionAsync(CancellationToken cancellationToken) in /Users/willbroadbelt/Documents/repos/couchbase/couchbase-net-client/src/Couchbase/Core/IO/Connections/ConnectionPoolBase.cs:line 65

   at Couchbase.Core.IO.Connections.DataFlow.DataFlowConnectionPool.<>c_DisplayClass28_0.<<AddConnectionsAsync>g_StartConnection|0>d.MoveNext() in /Users/willbroadbelt/Documents/repos/couchbase/couchbase-net-client/src/Couchbase/Core/IO/Connections/DataFlow/DataFlowConnectionPool.cs:line 251

— End of stack trace from previous location where exception was thrown —

   at Couchbase.Core.IO.Connections.DataFlow.DataFlowConnectionPool.AddConnectionsAsync(Int32 count, CancellationToken cancellationToken) in /Users/willbroadbelt/Documents/repos/couchbase/couchbase-net-client/src/Couchbase/Core/IO/Connections/DataFlow/DataFlowConnectionPool.cs:line 287

   at Couchbase.Core.IO.Connections.DataFlow.DataFlowConnectionPool.CleanupDeadConnectionsAsync() in /Users/willbroadbelt/Documents/repos/couchbase/couchbase-net-client/src/Couchbase/Core/IO/Connections/DataFlow/DataFlowConnectionPool.cs:line 358

Similar failure to NCBC-2422, but its throwing a IOException.

Here are the Logs: Sdk-ServiceRestart.log.zip , and ServiceRestart-KV.log.zip (SDKD).