SSL Ciphers? How to set reliable https Rest calls?

I'm working on a Unity client to generate game events with rest calls to a server backend. For security reasons we have to use secured HTTPS calls in our Rest API. However we're having issues making these Rest calls on Unity. The following SSL error is generated on our Unity client only.

"error:14077438:SSL routines:SSL23_GET_SERVER_HELLO:tlsv1 alert internal error"

It seems this is due to the Unity client using invalid SSL ciphers. I know we support TLS 1.2 for our ciphers, but I have no way of checking what ciphers Unity is using, or if there is anyway to specify what SSL options, if any, I can use.

Any help on how to fix this in Unity?