WiFi scans are not received when running startScan () on Android 8 with targetSdkVersion 26+

I'm working on an application that uses WiFi scans to work. I use the method startScan() of the class WifiManager and I have programmed a BroadcastReceiver to be notified when the scan has finished and the results can now be collected.

The code I have works perfectly on Android 7 and below, and even works on Android 8 if I set the% co_of% to 25 (Android 7) or lower.

The problem arises when I upload the targetSdkVersion to 26 and run the application on Android 8 (specifically on a Nexus 5X), and that WiFi scans are no longer received. As much as I execute targetSdkVersion I never get results. I repeat, if under% co_of% to 25, I will receive the results again without problems.

Reading the official documentation of Android, indicates that from Android 8 the esacneos will run much less frequently, but it is understood that they should work in the same way. Even on Android P this call is obsolete.

I understand that in Android P I will not be able to use this method, but in Android 8 yes, and yet it does not work.

I leave the startScan() documentation in case needed: Documentation

Does anyone know the reason for this behavior or does the same thing happen to someone?

EDIT:

This is the code that starts the scans :

public boolean startScan() {
   WifiManager wm = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
   if (!wm.isWifiEnabled()) {
     try {
       wm.setWifiEnabled(true);
     } catch (SecurityException e) {
       Log.w(LOG_TAG, "Error enabling wifi", e);
       return false;
     }
   }
   boolean started = wm.startScan();
   Log.d(LOG_TAG, "Scan started? " + started);
   return started;
}

This is the targetSdkVersion that receives the result of the scans (and it works except in Android 8 with targetSdkVersion 26 +):

public class InOutWifiScanResultsReceiver extends BroadcastReceiver {
   private static final String LOG_TAG = "ScanResults";

   @Override
   public void onReceive(Context context, Intent intent) {
     super.onReceive(context, intent); // Nunca entra aquí con Android 8 y targetSdkVersion 26+
     List<ScanResult> results = getWifiResults(context);
     Log.d(LOG_TAG, "Received results (" +  results.size() + " AP's)");
   }

   private static List<ScanResult> getWifiResults(Context context) {
      WifiManager wm = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
      try {
        return wm.getScanResults();
      } catch (SecurityException e) {
        return new ArrayList<>();
      }
   }
}

In the startScan() I have the following permissions and the BroadcastReceiver declared:

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>

 <receiver
    android:name=".InOutWifiScanResultsReceiver"
    android:exported="false">
    <intent-filter>
        <action android:name="android.net.wifi.SCAN_RESULTS"/>
    </intent-filter>
 </receiver>

The location permission is requested in Manifest , so I am sure that it is allowed, since I am the one who does the tests. I have also made sure that the location is activated (it is in maximum precision (gps + netword)).

The BroadcastReceiver seems to be declared because it works if the targetSdkVersion is 25 or less. I have also tried to put runtime in case it had something to do, but it seems that it does not.

I appreciate any help.