diff --git a/xcb/dxcbwmsupport.cpp b/xcb/dxcbwmsupport.cpp
index b2bba072..fdb82992 100644
--- a/xcb/dxcbwmsupport.cpp
+++ b/xcb/dxcbwmsupport.cpp
@@ -171,12 +171,13 @@ void DXcbWMSupport::updateHasComposite()
 
     xcb_connection_t *xcb_connection = DPlatformIntegration::xcbConnection()->xcb_connection();
 
-    auto atom = Utility::internAtom("_NET_KDE_COMPOSITE_TOGGLING");
+    // _NET_KDE_COMPOSITE_TOGGLING 为 KWin 私有 atom，非 KWin 环境下原本不存在属正常情况。
+    // intern 后 stage1 查不到属性会自然落入 stage2 的 _NET_WM_CM_S0 selection owner 探测。
+    // 仅在 X 连接异常时（如会话退出期）intern 才会失败，此时 stage2 同样无意义，静默返回
+    auto atom = Utility::internAtom("_NET_KDE_COMPOSITE_TOGGLING", false);
 
-    if (atom == 0) {
-        qWarning() << "The value of atom:_NET_KDE_COMPOSITE_TOGGLING is 0 !";
+    if (atom == XCB_NONE)
         return;
-    }
 
     xcb_window_t root = DPlatformIntegration::xcbConnection()->primaryScreen()->root();
 
diff --git a/xcb/utility_x11.cpp b/xcb/utility_x11.cpp
index b100a0de..3dcc5cfe 100644
--- a/xcb/utility_x11.cpp
+++ b/xcb/utility_x11.cpp
@@ -183,10 +183,18 @@ void Utility::updateMousePointForWindowMove(quint32 WId, bool finished/* = false
 // 新增：支持多屏幕的版本，接受自定义全局坐标
 void Utility::updateMousePointForWindowMove(quint32 WId, const QPoint &globalPos, bool finished/* = false*/)
 {
+    // internAtom() 默认 only_if_exists=true：_DEEPIN_MOVE_UPDATE 是 deepin kwin 的私有
+    // atom，窗管未创建它时查询返回 XCB_NONE，此时发送 type 为 0 的 ClientMessage，
+    // 会被窗管转发回客户端并触发 qtbase 的 "Unhandled client message" 告警。窗管不支持
+    // 该协议时直接跳过。
+    const xcb_atom_t moveUpdateType = internAtom("_DEEPIN_MOVE_UPDATE");
+    if (moveUpdateType == XCB_NONE)
+        return;
+
     xcb_client_message_event_t xev;
 
     xev.response_type = XCB_CLIENT_MESSAGE;
-    xev.type = internAtom("_DEEPIN_MOVE_UPDATE");
+    xev.type = moveUpdateType;
     xev.window = WId;
     xev.format = 32;
     xev.data.data32[0] = globalPos.x();