Can not turn on Hotspot Android

Question

My Android 7.1, I cannot turnon hotspot. If i click switch to turn on then It ok My code to turn on that: (similar example code in SO) Get wifi config

public WifiConfiguration getWifiApConfiguration(Context context) {
    WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
    try {
        Method method = wifiManager.getClass().getMethod("getWifiApConfiguration");
            return (WifiConfiguration) method.invoke(wifiManager);
        } catch (Exception e) {
            Log.e(this.getClass().toString(), "", e);
            return null;
    }
}

Turn on hotspot

public boolean setWifiEnabled(Context context, WifiConfiguration wifiConfig, boolean enabled) {
    WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
    try {
        if (enabled) { //disables wifi if it's already enabled
            wifiManager.setWifiEnabled(false);
        }

        Method method = wifiManager.getClass()
            .getMethod("setWifiApEnabled", WifiConfiguration.class, boolean.class);

        return (Boolean) method.invoke(wifiManager, wifiConfig, enabled);
    } catch (Exception e) {
        Log.e(this.getClass().toString(), "", e);
        return false;
    }
}

My app granded full permssions, I checked :

private void checkPermissions() {
    PackageManager pm = weakReference.get(). getPackageManager();
    String packageName =weakReference.get(). getPackageName();
    try {
        PackageInfo packageInfo = pm.getPackageInfo(packageName, PackageManager.GET_PERMISSIONS);
        String[] permissions = packageInfo.requestedPermissions;
            if (permissions != null) {
                for (String permission : permissions) {
                    int hasPermission = ContextCompat.checkSelfPermission(weakReference.get(), permission);
                    if (hasPermission != PackageManager.PERMISSION_GRANTED) {
                    Log.d("Permission", "Permission denied for: " + permission);
                    } else {
                    Log.d("Permission", "Permission granted for: " + permission);
                    }
                }
            }
        } catch (PackageManager.NameNotFoundException e) {
        e.printStackTrace();
    }
}

Permission granted for: android.permission.ACCESS_WIFI_STATE D/Permission: Permission granted for: android.permission.CHANGE_WIFI_STATE D/Permission: Permission granted for: android.permission.WRITE_SETTINGS D/Permission: Permission granted for: android.permission.CHANGE_NETWORK_STATE