diff --git a/backend/internal/modules/chat/repository.go b/backend/internal/modules/chat/repository.go
index 88e480e..19afa0c 100644
--- a/backend/internal/modules/chat/repository.go
+++ b/backend/internal/modules/chat/repository.go
@@ -191,14 +191,15 @@ func (r *Repository) EnsureSupportConversation(userID uint64) (*ConversationDTO,
 			Joins("JOIN chat_participants AS cp ON cp.conversation_id = c.id").
 			Where("c.type = ? AND cp.participant_type = ? AND cp.participant_id = ?", "general_support", "user", userID).
 			Order("c.id ASC").
-			First(&existing).Error
-		if err == nil {
+			Limit(1).
+			Find(&existing).Error
+		if err != nil {
+			return err
+		}
+		if existing.ID > 0 {
 			conversationID = existing.ID
 			return nil
 		}
-		if !errors.Is(err, gorm.ErrRecordNotFound) {
-			return err
-		}
 
 		now := time.Now()
 		conversation := model.ChatConversation{
diff --git a/frontend/src/api/client.ts b/frontend/src/api/client.ts
index f119a59..23896ed 100644
--- a/frontend/src/api/client.ts
+++ b/frontend/src/api/client.ts
@@ -73,7 +73,7 @@ function rejectPendingRequests(scope: AuthScope, error: unknown) {
   pendingRequests.forEach(({ reject }) => reject(error))
 }
 
-async function refreshToken(scope: AuthScope): Promise<string> {
+export async function refreshAccessToken(scope: AuthScope): Promise<string> {
   const refreshToken = getRefreshToken(scope)
   if (!refreshToken) throw new Error('no refresh token')
 
@@ -153,7 +153,7 @@ apiClient.interceptors.response.use(
 
     state.refreshing = true
     try {
-      const newToken = await refreshToken(scope)
+      const newToken = await refreshAccessToken(scope)
       resolvePendingRequests(scope, newToken)
       originalRequest._retry = true
       originalRequest.headers.Authorization = `Bearer ${newToken}`
diff --git a/frontend/src/composables/useChatSSE.ts b/frontend/src/composables/useChatSSE.ts
index 625002b..d93f5af 100644
--- a/frontend/src/composables/useChatSSE.ts
+++ b/frontend/src/composables/useChatSSE.ts
@@ -1,4 +1,5 @@
 import { onBeforeUnmount, ref, type Ref } from 'vue'
+import { refreshAccessToken } from '@/api/client'
 import { getAccessToken, type AuthScope } from '@/utils/authStorage'
 
 export interface SSEMessage {
@@ -29,6 +30,7 @@ export function useChatSSE(scope: AuthScope, endpoint: string) {
   let source: EventSource | null = null
   let reconnectTimer: ReturnType<typeof setTimeout> | null = null
   let stopped = false
+  let refreshing = false
   const handlers: EventHandler[] = []
 
   function onEvent(handler: EventHandler) {
@@ -36,6 +38,7 @@ export function useChatSSE(scope: AuthScope, endpoint: string) {
   }
 
   function connect() {
+    if (stopped || source) return
     const token = getAccessToken(scope)
     if (!token) return
 
@@ -60,18 +63,27 @@ export function useChatSSE(scope: AuthScope, endpoint: string) {
       } catch { /* ignore */ }
     })
 
-    source.onerror = () => {
+    source.onerror = async () => {
       connected.value = false
       source?.close()
       source = null
-      if (!stopped) {
-        reconnectTimer = setTimeout(connect, reconnectDelay)
+      if (stopped || refreshing) return
+
+      refreshing = true
+      try {
+        await refreshAccessToken(scope)
+        if (!stopped) {
+          reconnectTimer = setTimeout(connect, reconnectDelay)
+        }
+      } catch {
+        closeSource()
+      } finally {
+        refreshing = false
       }
     }
   }
 
-  function disconnect() {
-    stopped = true
+  function closeSource() {
     if (reconnectTimer) {
       clearTimeout(reconnectTimer)
       reconnectTimer = null
@@ -81,6 +93,21 @@ export function useChatSSE(scope: AuthScope, endpoint: string) {
     connected.value = false
   }
 
+  function handleAuthStorageChanged(event: Event) {
+    const detail = (event as CustomEvent<{ scope?: AuthScope }>).detail
+    if (detail?.scope !== scope || stopped) return
+    closeSource()
+    connect()
+  }
+
+  function disconnect() {
+    stopped = true
+    closeSource()
+    window.removeEventListener('auth-storage-changed', handleAuthStorageChanged)
+  }
+
+  window.addEventListener('auth-storage-changed', handleAuthStorageChanged)
+
   onBeforeUnmount(() => {
     disconnect()
   })