Compiler error when using configuration binder source generator with custom collections #91324

using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Hosting;
using System.Collections.ObjectModel;
using System.Net;

namespace ConfigBindRepro
{
    internal class Program
    {
        static void Main()
        {
            HostApplicationBuilder builder = Host.CreateEmptyApplicationBuilder(settings: null);
            builder.Configuration.AddInMemoryCollection(new KeyValuePair<string, string?>[]
            {
                 new KeyValuePair<string, string?>("ConfigBindRepro:EndPoints:0", "localhost"),
                 new KeyValuePair<string, string?>("ConfigBindRepro:Property", "true")
            });

            AClass instance = new();
#pragma warning disable SYSLIB1100
#pragma warning disable SYSLIB1101
            builder.Configuration.GetSection("ConfigBindRepro").Bind(instance);
#pragma warning restore

            BindToConfiguration(instance, builder.Configuration);
            if (instance.Property && instance.EndPoints.Any())
            {
                Console.WriteLine("OK");
            }
        }

        private static void BindToConfiguration(AClass settings, IConfiguration configuration)
        {
            var endpointsConfig = configuration.GetSection("ConfigBindRepro:EndPoints");
            foreach (var endpoint in endpointsConfig.GetChildren())
            {
                if (endpoint.Value is string)
                {
                    settings.EndPoints.Add(endpoint.Value);
                }
            }
        }
    }

    public class AClass
    {
        public EndPointCollection EndPoints { get; init; } = new EndPointCollection();

        public bool Property { get; set; } = false;
    }

    public sealed class EndPointCollection : Collection<EndPoint>, IEnumerable<EndPoint>
    {
        public EndPointCollection() { }

        public void Add(string hostAndPort)
        {
            EndPoint? endpoint;

            if (IPAddress.TryParse(hostAndPort, out IPAddress? address))
            {
                endpoint = new IPEndPoint(address, 0);
            }
            else
            {
                endpoint = new DnsEndPoint(hostAndPort, 0);
            }

            Add(endpoint);
        }
    }
}