Android Studio no access to internet

My app to access a simple JSON and display it runs perfectly fine on the emulator(PIXEL 2 API 24) but not on any actual device I connect to it. Tried with both S8 and Note10, neither have data saver on either.

I even checked the apps data use afterwards and it said "0 B".

Here are the files:

MainActivity.java:

package com.example.internettest;
import androidx.appcompat.app.AppCompatActivity;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
public class MainActivity extends AppCompatActivity {
Button button;
TextView textView;
ProgressDialog pd;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = (Button) findViewById(R.id.button);
textView = (TextView) findViewById(R.id.textView);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
new JsonTask().execute("http://46d30cf268b0.ngrok.io/LEATest/");
}
});
}
private class JsonTask extends AsyncTask<String, String, String> {
protected void onPreExecute() {
super.onPreExecute();
//pd = new ProgressDialog(MainActivity.this);
//pd.setMessage("Please wait");
//pd.setCancelable(false);
//pd.show();
}
protected String doInBackground(String... params) {
HttpURLConnection connection = null;
BufferedReader reader = null;
try {
URL url = new URL(params[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream stream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
StringBuffer buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line+"\n");
Log.d("Response: ", "> " + line);   //here u ll get whole response...... :-)
}
return buffer.toString();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (connection != null) {
connection.disconnect();
}
try {
if (reader != null) {
reader.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
//if (pd.isShowing()){
//    pd.dismiss();
//}
Toast toast = Toast.makeText(getApplicationContext(),
"Before Try = |" + result + "|",
Toast.LENGTH_SHORT);
toast.show();
textView.setText(result);
}
}
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.internettest">
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>

Here's the result of pressing the button on the emulator(all fake username/passwords):

Execure your JsonTask as follows -

new JsonTask().execute("https://46d30cf268b0.ngrok.io/LEATest/");

As suggested by @isthemartin, when you are running you app in actual device (S8 and Note10) the traffic is getting block because HTTP connection is not allowed.

Either you can add android:usesCleartextTraffic="true" but then you app will allow non secure HTTP connections.

I tried your API URL (https://46d30cf268b0.ngrok.io/LEATest/) is responding to the request so, why don't simply use it without making a security gap in your app.

probably your actual devices are blocking http connections, so in this case you need to enable those connections, check this post

Please add this code to your AndroidManifest.xml file.

   android:usesCleartextTraffic="true"

so the code can be like this :

 <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.internettest">
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:usesCleartextTraffic="true"
android:theme="@style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>

</manifest>