XDCR on TLS - Traffic not getting encrypted on Couchbase 4.5.1

We are able to use XDCR using Couchbase successfully on port 8091 with TLS enabled. However the traffic does not seem to be encrypted. Not sure why. We cannot XDCR to another Couchbase server using 18091 either. Does XDCR happen from one CB instance to another on 8091? Also how can we get TLS to be actually working.