Unable to present Medallia Digital survey forms on some versions of iOS

[TomSoPolaris]

We're using in-app survey forms to collect user feedback from Medallia Digital, https://www.medallia.com/solutions/digital

We noticed that when we use the Xamarin.iOS.SwiftRuntimeSupport package (v0.2.0) the survey forms aren't getting presented for iOS 11.0 devices.
If we use the Xamarin.Swift package, we have no issues.

We've written a Xamarin binding for the Medallia Digitial SDK version 3.4.2, so I'll include the DLL for that.

Here's the bit of code that shows the survey form

public void ShowForm(string formId, Action onSuccess = null, Action<MedalliaExternalError> onError = null)
{
    if (onSuccess == null)
    {
        onSuccess = new Action(() => { });
    }

    if (onError == null)
    {
        onError = new Action<MedalliaExternalError>((err) => { });
    }

    var nativeOnError = new Action<MDExternalError>((err) =>
    {
        onError.Invoke(new MedalliaExternalError
        {
            ErrorCode = (int)err.StatusCode,
            Message = err.Message
        });
    });

    MedalliaDigital.ShowForm(formId, onSuccess, nativeOnError);
}

MedalliaDigital.ShowForm() calls into:

[Export ("showForm:success:failure:")]
[BindingImpl (BindingImplOptions.GeneratedCode | BindingImplOptions.Optimizable)]
public unsafe static void ShowForm (string formId, [BlockProxy (typeof(ObjCRuntime.Trampolines.NIDAction))] Action success, [BlockProxy (typeof(ObjCRuntime.Trampolines.NIDActionArity1V0))] Action<MDExternalError> failure);

MedalliaiOSBinding.dll.zip

Test Info
iPhoneX iOS 11.0 - Medallia form didn't load

iPhoneXR iOS 12.0 - Medallia form loaded as expected