SSLStream - "The handshake failed due to an unexpected packet format"

I'm trying to implement a secure socket server using the code provided from the MS example:

https://docs.microsoft.com/en-us/dot...rity.sslstream

But when it tries to authenticate it gives the error:

"The handshake failed due to an unexpected packet format"

I'm testing this by running the server on a web hosting account using .NET core and the client on my computer. It works with regular sockets.

What could be the cause? How can I troubleshoot this?

Thanks