diff --git a/internal/web/job/node_traffic_sync_online_prune_test.go b/internal/web/job/node_traffic_sync_online_prune_test.go
new file mode 100644
index 000000000..907a6aa31
--- /dev/null
+++ b/internal/web/job/node_traffic_sync_online_prune_test.go
@@ -0,0 +1,45 @@
+package job
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/op/go-logging"
+
+	"github.com/mhsanaei/3x-ui/v3/internal/database"
+	"github.com/mhsanaei/3x-ui/v3/internal/database/model"
+	xuilogger "github.com/mhsanaei/3x-ui/v3/internal/logger"
+	"github.com/mhsanaei/3x-ui/v3/internal/web/runtime"
+	"github.com/mhsanaei/3x-ui/v3/internal/web/service"
+	"github.com/mhsanaei/3x-ui/v3/internal/xray"
+)
+
+// The sync tick is the only place that sees which nodes it no longer fetches, so it
+// must drop their online sets itself: a disabled node here, a deleted one below.
+func TestNodeTrafficSyncDropsOnlineClientsOfUnsyncedNodes(t *testing.T) {
+	xuilogger.InitLogger(logging.ERROR)
+	if err := database.InitDB(filepath.Join(t.TempDir(), "x-ui.db")); err != nil {
+		t.Fatalf("InitDB: %v", err)
+	}
+	t.Cleanup(func() { _ = database.CloseDB() })
+	runtime.SetManager(runtime.NewManager(runtime.LocalDeps{APIPort: func() int { return 0 }, SetNeedRestart: func() {}}))
+	t.Cleanup(func() { runtime.SetManager(nil) })
+	process := xray.NewTestProcess(nil, "")
+	t.Cleanup(service.SetXrayProcessForTest(process))
+
+	disabled := &model.Node{Name: "disabled", Address: "127.0.0.1", Port: 1, ApiToken: "tok", Enable: true, Status: "online"}
+	if err := database.GetDB().Create(disabled).Error; err != nil {
+		t.Fatalf("create node: %v", err)
+	}
+	if err := database.GetDB().Model(disabled).Update("enable", false).Error; err != nil {
+		t.Fatalf("disable node: %v", err)
+	}
+	process.SetNodeOnlineTree(disabled.Id, map[string][]string{"g-disabled": {"a@x"}})
+	process.SetNodeOnlineTree(disabled.Id+100, map[string][]string{"g-deleted": {"b@x"}})
+
+	NewNodeTrafficSyncJob().Run()
+
+	if got := process.GetMergedNodeTrees(); len(got) != 0 {
+		t.Fatalf("online sets after a sync tick = %v, want none for a disabled or deleted node", got)
+	}
+}
diff --git a/internal/web/service/xray_process_test_seam.go b/internal/web/service/xray_process_test_seam.go
new file mode 100644
index 000000000..fb4425bfc
--- /dev/null
+++ b/internal/web/service/xray_process_test_seam.go
@@ -0,0 +1,16 @@
+package service
+
+import "github.com/mhsanaei/3x-ui/v3/internal/xray"
+
+// SetXrayProcessForTest installs p as the running process and returns the restore func,
+// so tests in other packages can observe online state. Never call it in production.
+func SetXrayProcessForTest(p *xray.Process) (restore func()) {
+	previousProcess, previousResult := xrayState.snapshot()
+	xrayState.replace(p)
+	return func() {
+		xrayState.mu.Lock()
+		xrayState.process = previousProcess
+		xrayState.result = previousResult
+		xrayState.mu.Unlock()
+	}
+}