diff --git a/Sources/CodexBar/Settings/SettingsStore+Defaults.swift b/Sources/CodexBar/Settings/SettingsStore+Defaults.swift
index 06b4e8499..544b365d3 100644
--- a/Sources/CodexBar/Settings/SettingsStore+Defaults.swift
+++ b/Sources/CodexBar/Settings/SettingsStore+Defaults.swift
@@ -952,6 +952,7 @@ extension SettingsStore {
         get { self.mergedMenuLastSelectedWasOverviewStorage }
         set {
             self.mergedMenuLastSelectedWasOverviewStorage = newValue
+            diag4902("SETTING wasOverview=\(newValue)\n\(Thread.callStackSymbols.prefix(8).joined(separator: "\n"))")
             self.userDefaults.set(newValue, forKey: "mergedMenuLastSelectedWasOverview")
         }
     }
diff --git a/Sources/CodexBar/StatusItem/Diag4902.swift b/Sources/CodexBar/StatusItem/Diag4902.swift
new file mode 100644
index 000000000..e3a76bf06
--- /dev/null
+++ b/Sources/CodexBar/StatusItem/Diag4902.swift
@@ -0,0 +1,46 @@
+import AppKit
+import Foundation
+
+nonisolated func diag4902(_ message: String) {
+    let line = "\(Date().timeIntervalSince1970) \(message)\n"
+    guard let file = fopen("/tmp/cbdiag.log", "a") else { return }
+    fputs(line, file)
+    fclose(file)
+}
+
+@MainActor
+enum Diag4902 {
+    private static var installed = false
+    private static let observer = Diag4902Observer()
+    static func describe(_ menu: NSMenu?) -> String {
+        guard let menu else { return "nil" }
+        return "\(type(of: menu))#\(UInt(bitPattern: ObjectIdentifier(menu).hashValue) % 100_000)(items=\(menu.items.count),super=\(menu.supermenu != nil))"
+    }
+    static func install() {
+        guard !self.installed else { return }
+        self.installed = true
+        let names: [Notification.Name] = [
+            NSMenu.willSendActionNotification, NSMenu.didSendActionNotification,
+            NSMenu.didBeginTrackingNotification, NSMenu.didEndTrackingNotification,
+        ]
+        for name in names {
+            NotificationCenter.default.addObserver(
+                observer, selector: #selector(Diag4902Observer.handle(_:)), name: name, object: nil)
+        }
+        NSEvent.addLocalMonitorForEvents(matching: [.leftMouseDown, .leftMouseUp]) { event in
+            let window = event.window.map { String(describing: type(of: $0)) } ?? "nil"
+            diag4902("EVENT \(event.type.rawValue) window=\(window) loc=\(event.locationInWindow)")
+            return event
+        }
+    }
+}
+
+@MainActor
+final class Diag4902Observer: NSObject {
+    @objc func handle(_ note: Notification) {
+        let item = note.userInfo?["MenuItem"] as? NSMenuItem
+        let title = item?.title ?? "-"
+        let action = item?.action.map { NSStringFromSelector($0) } ?? "-"
+        diag4902("NOTE \(note.name.rawValue) menu=\(Diag4902.describe(note.object as? NSMenu)) item=\(title) action=\(action)")
+    }
+}
diff --git a/Sources/CodexBar/StatusItem/StatusItemController+HostedSubmenus.swift b/Sources/CodexBar/StatusItem/StatusItemController+HostedSubmenus.swift
index 213f14758..96f19ce98 100644
--- a/Sources/CodexBar/StatusItem/StatusItemController+HostedSubmenus.swift
+++ b/Sources/CodexBar/StatusItem/StatusItemController+HostedSubmenus.swift
@@ -181,6 +181,7 @@ extension StatusItemController {
             return
         }
 
+        diag4902("REFRESHHOSTED rebuild \(Diag4902.describe(menu))")
         menu.removeAllItems()
         let t0 = CACurrentMediaTime()
         MainThreadActivityBreadcrumb.push("refreshChart:\(identity.chartID)")
diff --git a/Sources/CodexBar/StatusItem/StatusItemController+Menu.swift b/Sources/CodexBar/StatusItem/StatusItemController+Menu.swift
index 0c9de281f..a4ecc529e 100644
--- a/Sources/CodexBar/StatusItem/StatusItemController+Menu.swift
+++ b/Sources/CodexBar/StatusItem/StatusItemController+Menu.swift
@@ -64,6 +64,8 @@ extension StatusItemController {
     }
 
     func menuWillOpen(_ menu: NSMenu) {
+        Diag4902.install()
+        diag4902("WILLOPEN \(Diag4902.describe(menu)) open=\(self.openMenus.count) overview=\(self.settings.mergedMenuLastSelectedWasOverview)")
         if menu.supermenu == nil {
             // Records interaction and may bring an adaptive timer forward; never refreshes
             // synchronously. Root opens only: hover-opening a hosted chart submenu must not kick
@@ -169,6 +171,7 @@ extension StatusItemController {
     }
 
     func menuDidClose(_ menu: NSMenu) {
+        diag4902("DIDCLOSE \(Diag4902.describe(menu)) highlighted=\(menu.highlightedItem?.title ?? "-") open=\(self.openMenus.count) overview=\(self.settings.mergedMenuLastSelectedWasOverview)")
         let wasHostedSubviewMenu = self.isHostedSubviewMenu(menu)
         self.forgetClosedMenu(menu)
         if wasHostedSubviewMenu {
@@ -219,6 +222,7 @@ extension StatusItemController {
     }
 
     func populateMenu(_ menu: NSMenu, provider: UsageProvider?) {
+        diag4902("POPULATE \(Diag4902.describe(menu)) overview=\(self.settings.mergedMenuLastSelectedWasOverview)")
         let trace = self.beginMenuOperationTrace(
             "populateMenu",
             breadcrumb: "populateMenu:\(provider?.rawValue ?? "merged")")
diff --git a/Sources/CodexBar/StatusItem/StatusItemController+MenuTracking.swift b/Sources/CodexBar/StatusItem/StatusItemController+MenuTracking.swift
index c47de97e9..ef0a3860b 100644
--- a/Sources/CodexBar/StatusItem/StatusItemController+MenuTracking.swift
+++ b/Sources/CodexBar/StatusItem/StatusItemController+MenuTracking.swift
@@ -171,6 +171,7 @@ extension StatusItemController {
     }
 
     func menu(_ menu: NSMenu, willHighlight item: NSMenuItem?, eventType: NSEvent.EventType?) {
+        diag4902("HIGHLIGHT \(Diag4902.describe(menu)) item=\(item?.title ?? "-") hasView=\(item?.view != nil) action=\(item?.action.map { NSStringFromSelector($0) } ?? "-") enabled=\(item?.isEnabled ?? false) target=\(item?.target != nil) event=\(eventType?.rawValue ?? 0)")
         let key = ObjectIdentifier(menu)
         let wasKeyboardHighlighted = self.keyboardHighlightedMenus.contains(key)
         switch eventType {
diff --git a/Sources/CodexBar/StatusItem/StatusItemController+OverviewSubmenus.swift b/Sources/CodexBar/StatusItem/StatusItemController+OverviewSubmenus.swift
index e98098dc1..661252ece 100644
--- a/Sources/CodexBar/StatusItem/StatusItemController+OverviewSubmenus.swift
+++ b/Sources/CodexBar/StatusItem/StatusItemController+OverviewSubmenus.swift
@@ -5,6 +5,22 @@ import CodexBarCore
 final class OverviewProviderDetailMenu: NSMenu {
     /// Hydrated rows carry no chart ID, so reopening reads the provider from here to rebuild a stale card.
     var provider: UsageProvider?
+    override func performActionForItem(at index: Int) {
+        diag4902("FLYOUT performActionForItem index=\(index) title=\(self.item(at: index)?.title ?? "?")")
+        super.performActionForItem(at: index)
+    }
+    override func removeAllItems() {
+        diag4902("FLYOUT removeAllItems count=\(self.items.count) highlighted=\(self.highlightedItem?.title ?? "-")")
+        super.removeAllItems()
+    }
+    override func cancelTracking() {
+        diag4902("FLYOUT cancelTracking\n\(Thread.callStackSymbols.prefix(10).joined(separator: "\n"))")
+        super.cancelTracking()
+    }
+    override func cancelTrackingWithoutAnimation() {
+        diag4902("FLYOUT cancelTrackingWithoutAnimation\n\(Thread.callStackSymbols.prefix(10).joined(separator: "\n"))")
+        super.cancelTrackingWithoutAnimation()
+    }
 }
 
 extension StatusItemController {
@@ -99,6 +115,7 @@ extension StatusItemController {
     }
 
     @objc func selectOverviewProvider(_ sender: NSMenuItem) {
+        diag4902("ACTION selectOverviewProvider(sender) rep=\(sender.representedObject ?? "nil") menu=\(Diag4902.describe(sender.menu)) super=\(Diag4902.describe(sender.menu?.supermenu))")
         guard let represented = sender.representedObject as? String,
               represented.hasPrefix(Self.overviewRowIdentifierPrefix)
         else {
@@ -115,6 +132,7 @@ extension StatusItemController {
     }
 
     func selectOverviewProvider(_ provider: ProviderInstanceID, menu: NSMenu) {
+        diag4902("ACTION selectOverviewProvider provider=\(provider.rawValue) wasOverview=\(self.settings.mergedMenuLastSelectedWasOverview)")
         if !self.settings.mergedMenuLastSelectedWasOverview, self.selectedMenuProvider == provider { return }
         self.preservingMergedSwitcherContentCachesDuringInvalidation {
             self.settings.mergedMenuLastSelectedWasOverview = false