Hey guys.   So I'll confirm for you that Tera1 clients break with Horizon Agent 7.7 or higher.

The problem is that the Tera1 client has a problem setting up the SSL connection to the Horizon Agent on port 4172 after it received the Server Hello SSL packet.  

The issue seems to be that Horizon 7.7 creates a self-signed certificates using SHA-256.  Of course, Tera1 only knows how to handle SHA-1.

I may not have a resolution for this anytime soon,  but attached are two packet captures; one to Horizon 7.6 and another to Horizon 7.7 for you to compare.