`ConnectTimeout` exception was throw when use `new ConfigurationOptions`

But if I use ConfigurationOptions.Parse, everything works fine.

StackExchange.Redis.RedisConnectionException: The message timed out in the backlog attempting to send because no connection became available (5000ms) - Last Connection Exception: It was not possible to connect to the redis server(s). ConnectTimeout, command=EVAL, timeout: 5000, inst: 0, qu: 0, qs: 0, aw: False, bw: CheckingForTimeout, rs: NotStarted, ws: Idle, in: 0, last-in: 0, cur-in: 0, sync-ops: 0, async-ops: 1, serverEndpoint: localhost:6379, conn-sec: n/a, aoc: 0, mc: 1/1/0, mgr: 10 of 10 available, clientName: Auth.Web, IOCP: (Busy=0,Free=1000,Min=1,Max=1000), WORKER: (Busy=1,Free=32766,Min=2,Max=32767), POOL: (Threads=3,QueuedItems=0,CompletedItems=54,Timers=2), v: 2.7.27.49176 (Please take a look at this article for some common client-side issues that can cause timeouts: https://stackexchange.github.io/StackExchange.Redis/Timeouts)

public static IServiceCollection AddCaching(this IServiceCollection services, IConfiguration configuration)
{
    services.AddStackExchangeRedisCache(options =>
    {

        var config = configuration.GetRedisConfiguration();
        var a = new ConfigurationOptions
        {
            ClientName = config.ClientName,
            DefaultDatabase = config.DefaultDatabase,
            EndPoints = new EndPointCollection([.. config.EndPoints.Cast<EndPoint>()])
        };
        var b = ConfigurationOptions.Parse(a.ToString());
        // Timeout when use a;
        options.ConfigurationOptions = a;
        // Worked when use b;
        // options.ConfigurationOptions = b;
    });

    return services;
}

Start by reproducing the timeout in the AddStackExchangeRedisCache configuration shown, comparing a directly initialized ConfigurationOptions with the result of ConfigurationOptions.Parse(a.ToString()). Inspect the ConfigurationOptions entry points and connection setup involved. Done means the cause is isolated and the two construction paths behave consistently, with a regression test if the relevant test location is identified.