WSDL FaultExceptions not caught

Question

I'm attempting to get FaultExceptions to hit for a WSDL service.

I have attempted the following:

• Created a new .Net 7.0 project in Visual studio
• Added the WSDL service reference for https://wsaimport.uni-login.dk/wsaimport-v7/ws?WSDL
• Called the generated WSDL method hentDataAftalerAsync
• Added below code to Program.cs

var binding = new CustomBinding(new TextMessageEncodingBindingElement(MessageVersion.CreateVersion(EnvelopeVersion.Soap12, AddressingVersion.None), Encoding.UTF8), new HttpsTransportBindingElement { MaxReceivedMessageSize = 104857600 });

var ws10Client = new ServiceReference2.WsaImportPortTypeClient(binding, new EndpointAddress("https://wsaimport.uni-login.dk/wsaimport-v7/ws"));
try
{

    var res = await ws10Client.hentDataAftalerAsync(new Credentials() { 
        wsBrugerid = "randomusername",
        wsPassword = "randompassword"
    });

    // this is reached if credentials are correct
    foreach (var item in res.hentDataAftalerResponse1.ToList())
    {
        Console.WriteLine(item);
    }
}
catch(FaultException<AuthentificationError> ex)
{
    // Neven hit (I expect this exception on wrong credentials)
    Console.WriteLine(ex.Message);
}
catch (FaultException ex)
{
    // Never hit
    Console.WriteLine(ex.Message);
}
catch (ProtocolException ex)
{
    // this exception is hit (but no info about the actual soap fault)
}
catch (Exception ex)
{
    // Never hit
    Console.WriteLine(ex.Message);
}

I have tested the hentDataAftaler operation in SoapUI, and when the credentials are wrong it does generate a SOAP response with a Fault of authentificationError.

So my question is, why is it not working for me in C#?