Repro for https://github.com/mysql-net/MySqlConnector/issues/1234

docker-compose.yml

version: '2'
services:
    master:
        image: mariadb:10.8
        environment:
            MYSQL_ROOT_PASSWORD: 'pass'
        command: mysqld --max-allowed-packet=96M --character-set-server=utf8mb4 --max-connections=250
        ports:
            - "3306:3306"

    maxscale:
        image: mariadb/maxscale:2.5
        depends_on:
            - master
        volumes:
            - ./maxscale.cnf.d:/etc/maxscale.cnf.d
        ports:
            - "4006:4006"  # readwrite port
            - "8989:8989"  # REST API port

maxscale.cnf

[server1]
type=server
address=master
port=3306
protocol=MariaDBBackend

[MariaDB-Monitor]
type=monitor
module=mariadbmon
servers=server1
user=root
password=pass
failcount=3
backend_connect_timeout=3
backend_write_timeout=3
backend_read_timeout=3
auto_failover=true
auto_rejoin=true
enforce_read_only_slaves=1

[Read-Write-Service]
type=service
router=readwritesplit
servers=server1
user=root
password=pass
master_failure_mode=fail_on_write
enable_root_user=true

[Read-Write-Listener]
type=listener
service=Read-Write-Service
protocol=MySQLClient
port=4006

maxscale.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net6.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Dapper" Version="2.0.123" />
    <PackageReference Include="MySqlConnector" Version="2.1.13" />
  </ItemGroup>

</Project>

Program.cs

using Dapper;
using MySqlConnector;

await MethodToRunAsync();

async Task Method1Async()
{
	using (var domain = new MySqlConnection())
	{
		await domain.OpenDBAsync();

		await domain.QueryAsync(@"SELECT * FROM mysql.user LIMIT 1");
	}
}

async Task Method2Async()
{
	using (var domain = new MySqlConnection())
	{
		Console.WriteLine("Before open");
		await domain.OpenDBAsync(); // Code blocks here after running Method1Async()
		Console.WriteLine("After open");

		using (var trans = await domain.BeginTransactionAsync())
		{
			await domain.ExecuteAsync("SELECT 1;", transaction: trans);

			await trans.RollbackAsync();
		}
	}
	Console.WriteLine("End of Method2");
}

async Task MethodToRunAsync()
{
	await Method1Async();
	await Method2Async(); // Blocks Here
}

public static class ExtensionMethods
{
	public static async Task OpenDBAsync(this MySqlConnection conn, bool allowUserVariables = false)
	{
		conn.ConnectionString = "server=127.0.0.1;port=4006;user=root;password=pass";
		await conn.OpenAsync();
	}
}