--- a/src/backend/replication/walreceiver.c
+++ b/src/backend/replication/walreceiver.c
@@ -517,6 +517,7 @@ WalReceiverMain(char *startup_data, size_t startup_data_len)
                       * let the startup process and primary server know about
                       * them.
                       */
+pg_usleep(300000);
                      XLogWalRcvFlush(false, startpointTLI);