diff --git a/pkg/controllers/follower/bidirectional_cache.go b/pkg/controllers/follower/bidirectional_cache.go
index 394b8576..8935eb5d 100644
--- a/pkg/controllers/follower/bidirectional_cache.go
+++ b/pkg/controllers/follower/bidirectional_cache.go
@@ -39,13 +39,13 @@ type bidirectionalCache[V1, V2 comparable] struct {
 func (c *bidirectionalCache[V1, V2]) lookup(key V1) sets.Set[V2] {
 	c.RLock()
 	defer c.RUnlock()
-	return c.cache[key]
+	return c.cache[key].Clone()
 }
 
 func (c *bidirectionalCache[V1, V2]) reverseLookup(key V2) sets.Set[V1] {
 	c.RLock()
 	defer c.RUnlock()
-	return c.reverseCache[key]
+	return c.reverseCache[key].Clone()
 }
 
 func (c *bidirectionalCache[V1, V2]) update(key V1, newValues sets.Set[V2]) {
diff --git a/pkg/controllers/status/controller.go b/pkg/controllers/status/controller.go
index 51c9c464..e33d9e40 100644
--- a/pkg/controllers/status/controller.go
+++ b/pkg/controllers/status/controller.go
@@ -560,11 +560,13 @@ func (s *StatusController) clusterStatuses(
 		clusterStatus = append(clusterStatus, resourceClusterStatus)
 	}
 
-	s.eventRecorder.Eventf(
-		fedObject,
-		corev1.EventTypeWarning, EventReasonGetObjectStatusError,
-		fmt.Sprintf("Failed to get some cluster status, error info: %s", strings.Join(errList, ". ")),
-	)
+	if len(errList) != 0 {
+		s.eventRecorder.Eventf(
+			fedObject,
+			corev1.EventTypeWarning, EventReasonGetObjectStatusError,
+			fmt.Sprintf("Failed to get some cluster status, error info: %s", strings.Join(errList, ". ")),
+		)
+	}
 
 	sort.Slice(clusterStatus, func(i, j int) bool {
 		return clusterStatus[i].ClusterName < clusterStatus[j].ClusterName