UnityWebRequest Post Not Returning Anything

The player gets registered in the database succesfully but it seems like the code after ‘yield return www.SendWebRequest()’ is never executed. Not a single Debug.Log() is showing up in my console.

Can someone please help me out?

C# code:

   private IEnumerator Register()
    {

        WWWForm form = new WWWForm();
        form.AddField("name", "Anonymous");
        form.AddField("highscore", "0");

        Debug.Log("Sending now!");
        UnityWebRequest www = UnityWebRequest.Post(API_URL + REGISTER_PAGE, form);
        
        yield return www.SendWebRequest();

    // These debug.logs don't show in console, but the player is added to the database without any issues.
        if (www.isNetworkError || www.isHttpError)
        {
            Debug.LogError("There was an error: " + www.error);
        }
        else
        {
            Debug.Log("Registered succesfully.");
            string name = www.downloadHandler.text;
            PlayerPrefs.SetString("name", name);
        }

    }

PHP code:

    include("../connection.php");
    
    $name = $_POST["name"];
    $highscore = $_POST["highscore"];

    $stmt = $connection->prepare("SELECT MAX(ID) FROM Leaderboard");
    $stmt->execute();
    $last_id = $stmt->fetchColumn();

    if($name === "Anonymous")
    {
        if($last_id == false)
        {
            $last_id = 0;
        }
        else
        {
            $last_id = ((int)$last_id);
            $last_id++;
        }
        $name = ($name."[".$last_id."]");
    }

    $stmt = $connection->prepare("INSERT INTO Leaderboard (name, highscore) VALUES (:name, :highscore)");
    $stmt->bindParam(':name', $name);
    $stmt->bindParam(':highscore', $highscore);
    $stmt->execute();

    echo $name;
    $connection = null;

IEnumerator doesnt continue after the yield return if your object is disable/destroyed, are you maybe disabeling it? can you try using this code and check if the issue it is that is not done, or simply not coninue after the request? (just remove the yield from the request and add the while)

www.SendWebRequest();

while(!www.isDone)
{
   Debug.Log("is waiting");
   yield return null;
}

Debug.Log("done!");