Serial Monitor Displaying Random Numbers

I’m building a robot that is controlled via an Android application through a WiFi connection using Serial, however I’m getting some issues in that the Serial Monitor is just displaying random numbers.

if (Serial.available() > 0) {
    inputData = Serial.read();
    Serial.print("Received: ");
    Serial.println(inputData, DEC);
}

As you can see in the attached picture, the app outputs the numbers using TCP and OutputStream and the Arduino reads them without a problem for a few seconds (displayed in green) and then it just starts displaying random numbers (displayed in red) and it doesn’t stop, it just keeps on going. It’s not from the app side because it shows me the logs whenever it outputs something, so I’m certain it’s from the Arduino side, I’ve checked all the connections and everything is working but the serial input is not working.

The numbers displayed in the red box are the ASCII character codes for "Received".

groundFungus:
The numbers displayed in the red box are the ASCII character codes for "Received".

I removed these two lines:

Serial.print("Received: ");
Serial.println(inputData, DEC);

And now it's working perfectly as expected, you my friend are a legend. Can't believe I didn't notice that before, feel like such an idiot right now!