diff --git a/src/backend/common-module/src/main/java/com/bbebig/commonmodule/kafka/dto/ChatMessageDto.java b/src/backend/common-module/src/main/java/com/bbebig/commonmodule/kafka/dto/ChatMessageDto.java
index c3fe055c..8b0fb318 100644
--- a/src/backend/common-module/src/main/java/com/bbebig/commonmodule/kafka/dto/ChatMessageDto.java
+++ b/src/backend/common-module/src/main/java/com/bbebig/commonmodule/kafka/dto/ChatMessageDto.java
@@ -49,11 +49,9 @@ public class ChatMessageDto {
 	private List<Long> targetMemberIds; // 메시지 대상자 목록 (DM일 경우)
 
 	// CREATE 시 필요
-	@PastOrPresent(message = "생성 시간은 현재 시간 이전이어야 합니다.")
 	private LocalDateTime createdAt;
 
 	// UPDATE 시 필요
-	@PastOrPresent(message = "수정 시간은 현재 시간 이전이어야 합니다.")
 	private LocalDateTime updatedAt;
 
 	// @JsonCreator와 @JsonProperty를 사용한 생성자
diff --git a/src/backend/common-module/src/main/java/com/bbebig/commonmodule/redis/domain/MemberPresenceStatus.java b/src/backend/common-module/src/main/java/com/bbebig/commonmodule/redis/domain/MemberPresenceStatus.java
index b969b8ad..8d81aad1 100644
--- a/src/backend/common-module/src/main/java/com/bbebig/commonmodule/redis/domain/MemberPresenceStatus.java
+++ b/src/backend/common-module/src/main/java/com/bbebig/commonmodule/redis/domain/MemberPresenceStatus.java
@@ -35,6 +35,15 @@ public void updateActualStatus(PresenceType actualStatus) {
 		calculateGlobalStatus();
 	}
 
+	public boolean existsDevice(String sessionId) {
+		for (DeviceInfo deviceInfo : devices) {
+			if (deviceInfo.getSocketSessionId().equals(sessionId)) {
+				return true;
+			}
+		}
+		return false;
+	}
+
 	public void updateCustomStatus(PresenceType customStatus) {
 		this.customStatus = customStatus;
 		calculateGlobalStatus();
@@ -48,7 +57,7 @@ public void deleteDevice(String sessionId) {
 		calculateGlobalStatus();
 	}
 
-	private void calculateGlobalStatus() {
+	public void calculateGlobalStatus() {
 		if (devices == null || devices.isEmpty() || actualStatus == PresenceType.OFFLINE) {
 			actualStatus = PresenceType.OFFLINE;
 			globalStatus = PresenceType.OFFLINE;
diff --git a/src/backend/state-server/src/main/java/com/bbebig/stateserver/service/ConnectionEventConsumerService.java b/src/backend/state-server/src/main/java/com/bbebig/stateserver/service/ConnectionEventConsumerService.java
index 70adf273..42445169 100644
--- a/src/backend/state-server/src/main/java/com/bbebig/stateserver/service/ConnectionEventConsumerService.java
+++ b/src/backend/state-server/src/main/java/com/bbebig/stateserver/service/ConnectionEventConsumerService.java
@@ -98,20 +98,24 @@ private MemberPresenceStatus handleConnectionEvent(ConnectionEventDto connection
 			memberPresenceStatus.updateLastActivityTime(LocalDateTime.now());
 		}
 
-		DeviceInfo deviceInfo = DeviceInfo.builder()
-				.platform(connectionEventDto.getPlatform())
-				.socketSessionId(connectionEventDto.getSocketSessionId())
-				.connectedServerIp(connectionEventDto.getConnectedServerIp())
-				.lastActiveTime(LocalDateTime.now())
-				.build();
-
-		// 안드로이드 기기인 경우, 로컬에 있던 정보가 있다면 현재 채널 정보를 업데이트
-		if (deviceInfo.getPlatform().equals("ANDROID") && connectionEventDto.getCurrentChannelType() != null) {
-			deviceInfo.updateCurrent(connectionEventDto.getCurrentChannelType(),
-					connectionEventDto.getCurrentChannelId(), connectionEventDto.getCurrentServerId());
+		if (!memberPresenceStatus.existsDevice(connectionEventDto.getSocketSessionId())) {
+			DeviceInfo deviceInfo = DeviceInfo.builder()
+					.platform(connectionEventDto.getPlatform())
+					.socketSessionId(connectionEventDto.getSocketSessionId())
+					.connectedServerIp(connectionEventDto.getConnectedServerIp())
+					.lastActiveTime(LocalDateTime.now())
+					.build();
+
+			// 안드로이드 기기인 경우, 로컬에 있던 정보가 있다면 현재 채널 정보를 업데이트
+			if (deviceInfo.getPlatform().equals("ANDROID") && connectionEventDto.getCurrentChannelType() != null) {
+				deviceInfo.updateCurrent(connectionEventDto.getCurrentChannelType(),
+						connectionEventDto.getCurrentChannelId(), connectionEventDto.getCurrentServerId());
+			}
+
+			memberPresenceStatus.getDevices().add(deviceInfo);
 		}
 
-		memberPresenceStatus.getDevices().add(deviceInfo);
+		memberPresenceStatus.calculateGlobalStatus();
 
 		memberRedisRepositoryImpl.saveMemberPresenceStatus(connectionEventDto.getMemberId(), memberPresenceStatus);
 
@@ -135,6 +139,7 @@ private MemberPresenceStatus handleDisconnectionEvent(ConnectionEventDto connect
 			memberRedisRepositoryImpl.saveMemberPresenceStatus(connectionEventDto.getMemberId(), memberPresenceStatus);
 		}
 
+		memberPresenceStatus.calculateGlobalStatus();
 		memberRedisRepositoryImpl.saveMemberPresenceStatus(connectionEventDto.getMemberId(), memberPresenceStatus);
 		return memberPresenceStatus;
 	}