diff --git a/backend/ai-core/internal/background/thinker.go b/backend/ai-core/internal/background/thinker.go
index d271eef..b9c4764 100644
--- a/backend/ai-core/internal/background/thinker.go
+++ b/backend/ai-core/internal/background/thinker.go
@@ -1660,8 +1660,8 @@ func (t *Thinker) buildThinkingUserPrompt(
 		sb.WriteString("刚有人和你聊完天。你想自然地在心里回味一下刚才的对话……\n")
 	case "silence":
 		t.muLock()
-		defer t.muUnlock()
 		silenceDuration := time.Since(t.lastUserTime())
+		t.muUnlock()
 
 		sb.WriteString(fmt.Sprintf("已经大约 %s 没有说话了。你有点想知道大家在做什么……\n",
 			formatDurationHuman(silenceDuration)))
@@ -1760,7 +1760,7 @@ func (t *Thinker) buildThinkingUserPrompt(
 
 		// OBv11 platform identity and available channels for proactive messaging.
 		t.muLock()
-		defer t.muUnlock()
+		t.muUnlock()
 		qqChannels := t.platformChannels
 		botUIDs := t.botUIDs
 		activeSID := t.activeSessionID
diff --git a/backend/platform-bridge/cmd/main.go b/backend/platform-bridge/cmd/main.go
index 1e9a8c6..8a44bd7 100644
--- a/backend/platform-bridge/cmd/main.go
+++ b/backend/platform-bridge/cmd/main.go
@@ -211,8 +211,16 @@ func main() {
 			response = &bridge.UnifiedResponse{Messages: []bridge.ResponseMessage{{DisplayType: "silent"}}, Platform: msg.Platform}
 
 		case isAdmin:
-			msg.RouteType = "normal"
-			response, routeErr = forwardToAICore(cfg, msg, "text", chatUserID, groupSessionID, imageURLs, videoURLs, voiceURLs, isAdmin)
+			// 管理员在群里@别人(非bot)时，用 group_ambient 避免昔涟频繁插嘴
+			if msg.ChannelType == "group" && !isBotMentioned {
+				msg.RouteType = "group_ambient"
+				namespace := buildMemoryNamespace(msg.Platform, msg.ChannelType, msg.ChannelID)
+				fireSilent(namespace, imageURLs, videoURLs, voiceURLs)
+				response, routeErr = forwardToAICore(cfg, msg, "group_ambient", chatUserID, groupSessionID, imageURLs, videoURLs, voiceURLs, isAdmin)
+			} else {
+				msg.RouteType = "normal"
+				response, routeErr = forwardToAICore(cfg, msg, "text", chatUserID, groupSessionID, imageURLs, videoURLs, voiceURLs, isAdmin)
+			}
 
 		case isBotMentioned:
 			msg.RouteType = "normal"