rw-core dropping packet-in

{"level":"error","ts":"2019-08-15T15:51:42.839Z","msg":"failed-to-send-packet","instanceId":"voltha-rw-core-11-6dcdc85d4c-bswjt","caller":"grpc_nbi_api_handler.ReceivePacketsIn:827","error":"rpc error: code = Internal desc = transport: transport: the stream is done or WriteHeader was already called","stacktrace":"github.com/opencord/voltha-go/common/log.Errorw\n\t/go/src/github.com/opencord/voltha-go/common/log/log.go:700\ngithub.com/opencord/voltha-go/rw_core/core.(*APIHandler).ReceivePacketsIn\n\t/go/src/github.com/opencord/voltha-go/rw_core/core/grpc_nbi_api_handler.go:827\ngithub.com/opencord/voltha-go/vendor/github.com/opencord/voltha-protos/go/voltha._VolthaService_ReceivePacketsIn_Handler\n\t/go/src/github.com/opencord/voltha-go/vendor/github.com/opencord/voltha-protos/go/voltha/voltha.pb.go:3822\ngithub.com/opencord/voltha-go/vendor/google.golang.org/grpc.(*Server).processStreamingRPC\n\t/go/src/github.com/opencord/voltha-go/vendor/google.golang.org/grpc/server.go:1175\ngithub.com/opencord/voltha-go/vendor/google.golang.org/grpc.(*Server).handleStream\n\t/go/src/github.com/opencord/voltha-go/vendor/google.golang.org/grpc/server.go:1254\ngithub.com/opencord/voltha-go/vendor/google.golang.org/grpc.(*Server).serveStreams.func1.1\n\t/go/src/github.com/opencord/voltha-go/vendor/google.golang.org/grpc/server.go:690"}