Thank you for the fast reply. This solved the issue.

I created 2 console applications (.NET Core 3.1 and .NET Framework 4.6.1) running exactly the same code:


public static async Task SendHelloWorld()
{
LogManager.SetLoggerFactory(new ConsoleLogFactory(LogLevel.Verbose));

using (SmppClient client = new SmppClient())
{
try
{
if (await client ...