Unable to call web data ("TlsException: The server stopped the handshake")

Any help is appreciated here, as this bug is breaking my game :(

I'm trying to call a web JSON API to fill some text in my UI. I'm using the code below to get the raw JSON. Up until now it worked like a charm, but now it's broken and throws a handshake error ("TlsException: The server stopped the handshake"). I did not recently make any changes to this script, and it had been working for a good while.

I believe this is an issue with Mono not trusting the certificate for this website, but after some extensive trial-and-error googling I'm still not exactly sure how to fix it. Please note that I copied and pasted the majority of this code from another question on the forums - I am not at all an expert on certificate validation.

Thank you in advance for your help :)

     public static string webData;
     public Text myText;
 
     void Start () {
         ServicePointManager.ServerCertificateValidationCallback = MyRemoteCertificateValidationCallback;
         System.Net.WebClient wc = new System.Net.WebClient();
         byte[] raw = wc.DownloadData("https://opentdb.com/api.php?amount=1&type=multiple");
         webData = System.Text.Encoding.UTF8.GetString(raw);
     }
 
     public bool MyRemoteCertificateValidationCallback(System.Object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors) {
         bool isOk = true;
         // If there are errors in the certificate chain, look at each error to determine the cause.
         if (sslPolicyErrors != SslPolicyErrors.None) {
             for (int i=0; i<chain.ChainStatus.Length; i++) {
                 if (chain.ChainStatus [i].Status != X509ChainStatusFlags.RevocationStatusUnknown) {
                     chain.ChainPolicy.RevocationFlag = X509RevocationFlag.EntireChain;
                     chain.ChainPolicy.RevocationMode = X509RevocationMode.Online;
                     chain.ChainPolicy.UrlRetrievalTimeout = new TimeSpan (0, 1, 0);
                     chain.ChainPolicy.VerificationFlags = X509VerificationFlags.AllFlags;
                     bool chainIsValid = chain.Build ((X509Certificate2)certificate);
                     if (!chainIsValid) {
                         isOk = false;
                     }
                 }
             }
         }
         return isOk;
     }
 }