Forcing a particular SSL protocol for an nginx proxying server

The possible solution to your Problem is decribed here

You have to downgrade to OpenSSL 1.0.0 in the Nginx system because of a bug.

This is due to the fact that when you try to Nginx compiled with Openssl version 1.0.1 in which they have introduced TLSv1.1 and TLSv1.2 whenever Nginx is trying to connect to backend server it will reset connect with peer closed connection in SSL handshake (54: Connection reset by peer) while SSL handshaking to upstream in Nginx Debug Logs which means backend does not have TLSv1.1 and TLSv1.2 support.

If Load Balancer is being used then you/client need to upgrade their Load Balancer Frimware.