*** a/src/backend/replication/syncrep.c
--- b/src/backend/replication/syncrep.c
***************
*** 397,402 **** SyncRepReleaseWaiters(void)
--- 397,403 ----
  		volatile WalSnd *walsnd = &walsndctl->walsnds[i];
  
  		if (walsnd->pid != 0 &&
+ 			walsnd->state == WALSNDSTATE_STREAMING &&
  			walsnd->sync_standby_priority > 0 &&
  			(priority == 0 ||
  			 priority > walsnd->sync_standby_priority))