tls_alert handshake failure

Hi, I'm calling the api from the load balancer nginx server to the api server (code written in Elixir) and it throws the following error. I'm still not sure whether it has to do with the OS or TLS?

OS: Ubuntu 16.04 Erlang: Elixir 1.6.5 (Erlang OTP 20)

Error: Request: POST /api/bill/payment ** (exit) an exception was raised: ** (HTTPoison.Error) {:tls_alert, 'handshake failure'} (httpoison) lib/httpoison.ex:66: HTTPoison.request!/5

I know Ubuntu version is very old. However the same api endpoint used to work before like year ago. There isn't any change in the code though.

May I know is this something to do with AWS certificate? regards Riaz