I am also experiencing many problems.
I have followed the steps of the mnet documentation as much as I can and added the $CFG->opensslcnf = in my config page.
But when I try to save I always get the following if the dubugin is on :
Request for https://myfakemoodlesite.com returned unexpected resultLower in the page the current public key is empty.
If I print the error is seems to refer to curl error 51 : CURLE_PEER_FAILED_VERIFICATION
I'm not sure what else to try. Could the fact that both my moodles are on the same server be a problem?
Or that they have the same secruity certificate?