Android WiFi direct requestPeers not finding any peers nearby

Background: Device used: Samsung Galaxy Note 10+, Samsung Galaxy S8

1. I'm developing an Android application that uses WiFi-direct to transfer photos.
2. In order to do so, I first establish BLE connection between two devices, so that they can exchange macAddress data through BLE characteristics.
3. Upon Bluetooth service is discovered in "OnServiceDiscovered" callback method, I call "discoverPeers" method.
4. When "discoverPeers()" succeeds, WifiP2PManager calls "requestPeers(channel, PeerListListener)"
5. Strangely, despite many wifi devices being present, the wifi device list is empty, always.

Here is the code

public void discoverWifiPeers() {
        manager.discoverPeers(channel, new WifiP2pManager.ActionListener() {
            @Override
            public void onSuccess() {
                Log.e("INFO", "Discover Peers succeeded");
                manager.requestPeers(channel, myPeerListListener);
            }
            @Override
            public void onFailure(int reasonCode) {
                Log.e("Error", "Discover Peers failed");
            }
        });
    }

private WifiP2pManager.PeerListListener myPeerListListener = new WifiP2pManager.PeerListListener() {
        @Override
        public void onPeersAvailable(WifiP2pDeviceList wifiP2pDeviceList) {
            for (WifiP2pDevice device : wifiP2pDeviceList.getDeviceList())
            {
                if(!wifiDeviceList.contains(device))
                    wifiDeviceList.add(device);
            }
            Log.i(CommonConstants.INFO, "onPeersAvailable() - devicelist =>" + wifiDeviceList.size());
        }
    };

Measures I had taken:

• I searched lots of blogs and StackOverflow questions for this, and so far all of them pointed coarse location permission. I added the code below.

private void requestCoarseLocation(){
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION)
                != PackageManager.PERMISSION_GRANTED) {
            if (ActivityCompat.shouldShowRequestPermissionRationale(this,
                    Manifest.permission.ACCESS_COARSE_LOCATION)) {

            } else {
                ActivityCompat.requestPermissions(this,
                        new String[]{Manifest.permission.ACCESS_COARSE_LOCATION},
                        CommonConstants.REQUEST_COARSE_LOCATION
                );
            }
        }
    }
}

• It gave Wifi device list for the very first time I added the COARSE_PERMISSION, but after that one time it resumed showing empty list for the WiFi list.

How can I always guarantee to have the wifi device list of devices in proximity?