diff --git a/src/com/android/settings/connecteddevice/fastpair/FastPairDeviceGroupController.java b/src/com/android/settings/connecteddevice/fastpair/FastPairDeviceGroupController.java
index ac117f1..8918f01 100644
--- a/src/com/android/settings/connecteddevice/fastpair/FastPairDeviceGroupController.java
+++ b/src/com/android/settings/connecteddevice/fastpair/FastPairDeviceGroupController.java
@@ -22,6 +22,7 @@
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.content.pm.PackageManager;
+import android.util.Log;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.VisibleForTesting;
@@ -44,7 +45,10 @@
 public class FastPairDeviceGroupController extends BasePreferenceController
         implements PreferenceControllerMixin, DefaultLifecycleObserver, DevicePreferenceCallback {
 
+    private static final String TAG = "FastPairDeviceGroupCtr";
+
     private static final String KEY = "fast_pair_device_list";
+    private static final boolean DEBUG = Log.isLoggable(TAG, Log.DEBUG);
 
     @VisibleForTesting PreferenceGroup mPreferenceGroup;
     private final FastPairDeviceUpdater mFastPairDeviceUpdater;
@@ -68,6 +72,7 @@
             mFastPairDeviceUpdater =
                     fastPairFeatureProvider.getFastPairDeviceUpdater(context, this);
         } else {
+            Log.d(TAG, "Flag disabled. Ignored.");
             mFastPairDeviceUpdater = null;
         }
         mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
@@ -78,6 +83,10 @@
     public void onStart(@NonNull LifecycleOwner owner) {
         if (mFastPairDeviceUpdater != null) {
             mFastPairDeviceUpdater.registerCallback();
+        } else {
+            if (DEBUG) {
+                Log.d(TAG, "Callback register: Fast Pair device updater is null. Ignore.");
+            }
         }
         mContext.registerReceiver(mReceiver, mIntentFilter, Context.RECEIVER_EXPORTED_UNAUDITED);
     }
@@ -86,6 +95,10 @@
     public void onStop(@NonNull LifecycleOwner owner) {
         if (mFastPairDeviceUpdater != null) {
             mFastPairDeviceUpdater.unregisterCallback();
+        } else {
+            if (DEBUG) {
+                Log.d(TAG, "Callback unregister: Fast Pair device updater is null. Ignore.");
+            }
         }
         mContext.unregisterReceiver(mReceiver);
     }
@@ -117,14 +130,24 @@
 
     @Override
     public void onDeviceAdded(Preference preference) {
-        if (preference == null) return;
+        if (preference == null) {
+            if (DEBUG) {
+                Log.d(TAG, "onDeviceAdded receives null preference. Ignore.");
+            }
+            return;
+        }
         mPreferenceGroup.addPreference(preference);
         updatePreferenceVisibility();
     }
 
     @Override
     public void onDeviceRemoved(Preference preference) {
-        if (preference == null) return;
+        if (preference == null) {
+            if (DEBUG) {
+                Log.d(TAG, "onDeviceRemoved receives null preference. Ignore.");
+            }
+            return;
+        }
         mPreferenceGroup.removePreference(preference);
         updatePreferenceVisibility();
     }
diff --git a/src/com/android/settings/connecteddevice/fastpair/FastPairDevicePreferenceController.java b/src/com/android/settings/connecteddevice/fastpair/FastPairDevicePreferenceController.java
index 6a5b6b9..76c9d00 100644
--- a/src/com/android/settings/connecteddevice/fastpair/FastPairDevicePreferenceController.java
+++ b/src/com/android/settings/connecteddevice/fastpair/FastPairDevicePreferenceController.java
@@ -81,6 +81,7 @@
             mFastPairDeviceUpdater =
                     fastPairFeatureProvider.getFastPairDeviceUpdater(context, this);
         } else {
+            Log.d(TAG, "Flag disabled. Ignore.");
             mFastPairDeviceUpdater = null;
         }
         mIntentFilter = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
@@ -91,6 +92,10 @@
     public void onStart(@NonNull LifecycleOwner owner) {
         if (mFastPairDeviceUpdater != null) {
             mFastPairDeviceUpdater.registerCallback();
+        } else {
+            if (DEBUG) {
+                Log.d(TAG, "Callback register: Fast Pair device updater is null. Ignore.");
+            }
         }
         mContext.registerReceiver(mReceiver, mIntentFilter, Context.RECEIVER_EXPORTED_UNAUDITED);
     }
@@ -99,6 +104,10 @@
     public void onStop(@NonNull LifecycleOwner owner) {
         if (mFastPairDeviceUpdater != null) {
             mFastPairDeviceUpdater.unregisterCallback();
+        } else {
+            if (DEBUG) {
+                Log.d(TAG, "Callback unregister: Fast Pair device updater is null. Ignore.");
+            }
         }
         mContext.unregisterReceiver(mReceiver);
     }