DotNetty SSL/TLS problem in Unity

1. What happened
The SSL/TLS in DotNetty is not working in Unity. But it's working in normal DotNet application.I have a lot of existing code based on DotNetty. So I need it correctly run in Unity. Is there something that I can do on my side or DotNetty side? Thank you.

There must be something different between normal DotNet application and Unity. But I'm sure that the SSL/TLS should be working in Unity. Because the websocket-sharp is working in Unity with SSL/TLS.
https://github.com/sta/websocket-sharp/

Here's a normal DotNet application which is working as a reference.
https://github.com/SetoKaiba/TestNetty

Here's a Unity application which is not working as a reference.
https://github.com/SetoKaiba/BugProject

2. How can we reproduce it using the example you attached
1) Play the SampleScene
2) You will see that the AggregatedFullHttpResponse is never printed. The TlsHandler is not working correctly.
3) Run the normal DotNet application, you will see that the AggregatedFullHttpResponse is correctly printed.