diff --git a/lib/dbus/bindings.js b/lib/dbus/bindings.js
index 648d75f2..6ba2377b 100644
--- a/lib/dbus/bindings.js
+++ b/lib/dbus/bindings.js
@@ -299,6 +299,7 @@ class DbusBindings extends EventEmitter {
     if (this._scanServiceUuids.length > 0) {
       filter.UUIDs = new Variant('as', this._scanServiceUuids.map(expandUuid));
     }
+    debug('startScanning: filter UUIDs=%j duplicates=%s', this._scanServiceUuids, !!allowDuplicates);
     try {
       await this._adapterIface.SetDiscoveryFilter(filter);
     } catch (err) {
@@ -307,7 +308,37 @@ class DbusBindings extends EventEmitter {
     if (!this._isScanning) {
       await this._adapterIface.StartDiscovery();
       this._isScanning = true;
+      debug('startScanning: StartDiscovery issued');
+    } else {
+      debug('startScanning: already scanning, skipping StartDiscovery');
     }
+
+    // Re-read BlueZ's object tree and surface cached devices.
+    // BlueZ won't emit InterfacesAdded for devices already in its cache,
+    // so without this refresh a new scan would miss them entirely.
+    try {
+      const managed = await this._objectManager.GetManagedObjects();
+      let surfacedCount = 0;
+      for (const [path, ifaces] of Object.entries(managed)) {
+        const unwrapped = {};
+        for (const [iface, props] of Object.entries(ifaces)) {
+          unwrapped[iface] = unwrapDict(props);
+        }
+        this._objects.set(path, Object.assign(this._objects.get(path) || {}, unwrapped));
+        if (unwrapped[DEVICE_IFACE] && this._isUnderAdapter(path)) {
+          surfacedCount++;
+          const addr = unwrapped[DEVICE_IFACE].Address || 'unknown';
+          const name = unwrapped[DEVICE_IFACE].Name || unwrapped[DEVICE_IFACE].Alias || '';
+          const uuids = unwrapped[DEVICE_IFACE].UUIDs || [];
+          debug('startScanning: re-surfacing cached device %s addr=%s name=%s uuids=%j', path, addr, name, uuids);
+          this._handleDeviceProps(path, unwrapped[DEVICE_IFACE]);
+        }
+      }
+      debug('startScanning: re-surfaced %d cached device(s) from BlueZ', surfacedCount);
+    } catch (err) {
+      debug('startScanning: GetManagedObjects refresh failed: %s', err.message);
+    }
+
     this.emit('scanStart', !!allowDuplicates);
   }
 
@@ -341,6 +372,9 @@ class DbusBindings extends EventEmitter {
     this._objects.set(path, Object.assign(existing, unwrapped));
 
     if (unwrapped[DEVICE_IFACE] && this._isUnderAdapter(path)) {
+      const addr = unwrapped[DEVICE_IFACE].Address || 'unknown';
+      const name = unwrapped[DEVICE_IFACE].Name || unwrapped[DEVICE_IFACE].Alias || '';
+      debug('InterfacesAdded: new device %s addr=%s name=%s', path, addr, name);
       this._handleDeviceProps(path, unwrapped[DEVICE_IFACE]);
     }
     // Trigger services-resolved processing if a device just gained ServicesResolved
@@ -384,6 +418,10 @@ class DbusBindings extends EventEmitter {
     const address = props.Address || devicePathToAddress(path);
     if (!address) return;
     const id = addressToId(address);
+    const name = props.Name || props.Alias || '';
+    const serviceData = props.ServiceData ? Object.keys(props.ServiceData) : [];
+    const uuids = props.UUIDs || [];
+    debug('handleDeviceProps: id=%s addr=%s name=%s uuids=%j serviceData=%j rssi=%s', id, address, name, uuids, serviceData, props.RSSI);
     let device = this._devices.get(id);
     if (!device) {
       device = {
diff --git a/lib/hci-socket/gap.js b/lib/hci-socket/gap.js
index 4659c09e..a3069faf 100644
--- a/lib/hci-socket/gap.js
+++ b/lib/hci-socket/gap.js
@@ -93,14 +93,19 @@ Gap.prototype.onHciLeScanEnableSet = function (status) {
 
 // Called when we see the actual command "LE Set Scan Enable"
 Gap.prototype.onLeScanEnableSetCmd = function (enable, filterDuplicates) {
+  debug('onLeScanEnableSetCmd: enable=%s filterDuplicates=%s scanState=%s ownFilterDuplicates=%s',
+    enable, filterDuplicates, this._scanState, this._scanFilterDuplicates);
   // Check to see if the new settings differ from what we expect.
   // If we are scanning, then a change happens if the new command stops
   // scanning or if duplicate filtering changes.
   // If we are not scanning, then a change happens if scanning was enabled.
   if (this._scanState === 'starting' || this._scanState === 'started') {
     if (!enable) {
+      debug('onLeScanEnableSetCmd: external process stopped our scan');
       this.emit('scanStop');
     } else if (this._scanFilterDuplicates !== filterDuplicates) {
+      debug('onLeScanEnableSetCmd: external process changed filterDuplicates from %s to %s',
+        this._scanFilterDuplicates, filterDuplicates);
       this._scanFilterDuplicates = filterDuplicates;
 
       this.emit('scanStart', this._scanFilterDuplicates);
@@ -109,6 +114,7 @@ Gap.prototype.onLeScanEnableSetCmd = function (enable, filterDuplicates) {
     (this._scanState === 'stopping' || this._scanState === 'stopped') &&
     enable
   ) {
+    debug('onLeScanEnableSetCmd: external process started scanning while we were %s', this._scanState);
     // Someone started scanning on us.
     this.emit('scanStart', this._scanFilterDuplicates);
   }
@@ -165,12 +171,17 @@ Gap.prototype.onHciLeAdvertisingReport = function (
   };
 
   // only report after a scan response event or if non-connectable or more than one discovery without a scan response, so more data can be collected
-  if (
+  const willEmit =
     type === LE_META_EVENT_TYPE_SCAN_RESPONSE ||
     !connectable ||
     (discoveryCount > 1 && !hasScanResponse) ||
-    process.env.NOBLE_REPORT_ALL_HCI_EVENTS
-  ) {
+    process.env.NOBLE_REPORT_ALL_HCI_EVENTS;
+
+  debug('adv: addr=%s type=0x%s name=%s rssi=%d count=%d connectable=%s hasScanResponse=%s → %s',
+    address, type.toString(16), advertisement.localName || '', rssi, discoveryCount,
+    connectable, hasScanResponse, willEmit ? 'EMIT' : 'SUPPRESS (waiting for scan response)');
+
+  if (willEmit) {
     this.emit(
       'discover',
       status,
@@ -238,12 +249,17 @@ Gap.prototype.onHciLeExtendedAdvertisingReport = function (
   };
 
   // only report after a scan response event or if non-connectable or more than one discovery without a scan response, so more data can be collected
-  if (
+  const willEmit =
     type & LE_META_EXTENDED_EVENT_TYPE_SCAN_RESPONSE_MASK ||
     (!connectable && !incomplete) ||
     (discoveryCount > 1 && !hasScanResponse) ||
-    process.env.NOBLE_REPORT_ALL_HCI_EVENTS
-  ) {
+    process.env.NOBLE_REPORT_ALL_HCI_EVENTS;
+
+  debug('ext-adv: addr=%s type=0x%s name=%s rssi=%d count=%d connectable=%s incomplete=%s hasScanResponse=%s → %s',
+    address, type.toString(16), advertisement.localName || '', rssi, discoveryCount,
+    connectable, incomplete, hasScanResponse, willEmit ? 'EMIT' : 'SUPPRESS');
+
+  if (willEmit) {
     this.emit(
       'discover',
       status,