Firebird Client connection pooling doesn't work correctly

Question

A connection pool in FirebirdClient seems to be broken. It should queue my queries when is already empty but I get an exception instead. I need a help how to deal with this problem.

I'm using FirebirdClient version 7.1.1. I am running a console .Net Core app (version 2.2.0) and I am connecting Firebird 3.0. I execute 4 concurrent queries. I have MaxPoolSize set to 2. So there is not enough connections to execute all queries.

using System;
using System.Threading.Tasks;
using FirebirdSql.Data.FirebirdClient;

namespace ConsoleApp3
{
    class Program
    {
        private const string connStr =
            "User=SYSDBA;Password=***;Database=/opt/firebird/bases/db.fdb;DataSource=192.168.2.1;Port=3050;Connection lifetime=15;Pooling=true; MinPoolSize=0;MaxPoolSize=2;";

        private static void Connect(string name)
        {
            Console.WriteLine($">>>>>>STARTING>>>>>>>>>>>> {name}");

            var cmd = new FbCommand(
                "select count(*) from MON$ATTACHMENTS a where a.mon$remote_process like '%ConsoleApp3.dll'");
            using (cmd.Connection = new FbConnection(connStr))
            {
                try
                {
                    cmd.Connection.Open();
                    var id = Convert.ToInt32(cmd.ExecuteScalar());
                    Task.Delay(1000);
                    Console.WriteLine($">>>>>>Done>>>>>>>>>>>> {name} RESULT {id}");
                }
                catch (Exception e)
                {
                    Console.WriteLine($">>>>>>>ERROR>>>>>>>>>>> {name}");
                    Console.WriteLine(e);
                }
            }
        }

        static void Main(string[] args)
        {
            var t1 = Task.Run(() => Connect("conn1"));
            var t2 = Task.Run(() => Connect("conn2"));
            var t3 = Task.Run(() => Connect("conn3"));
            var t4 = Task.Run(() => Connect("conn4"));

            Task.WaitAll(t1, t2, t3, t4);

            Console.WriteLine(">>>>>>>>>>>> DONE>>>>>>>>>>>>>>>");
            Console.ReadKey();
        }
    }
}

I expect that queries that don't have free connection will be queued and executed when the connection to database will be reclaimed to the connection pool but instead I get a following exception:

System.InvalidOperationException: Connection pool is full.
   at FirebirdSql.Data.FirebirdClient.FbConnectionPoolManager.Pool.CreateNewConnectionIfPossibleImpl(ConnectionString connectionString)
   at FirebirdSql.Data.FirebirdClient.FbConnectionPoolManager.Pool.GetConnection(FbConnection owner)
   at FirebirdSql.Data.FirebirdClient.FbConnection.Open()
   at ConsoleApp3.Program.Connect(String name) in C:\Projects\ConsoleApp3\ConsoleApp3\Program.cs:line 22