Hi @michaelc123,
The issue is with your certificate:
2017/02/13 15:21:15 [error] 4885#4885: *1 SSL_do_handshake() failed (SSL: error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol) while SSL handshaking to upstream
You need to make sure your pem file also includes the CA cert.
Until:
$ curl -I -v https://myserver.mydomain:8443
returns correctly, no point in checking other things.