Find the answer to your question
We switched our platform notification listener to HTTPS but we are not receiving any Platform notifications since. Why?
One of the reasons could be your server requires SNI but provides a wildcard certificate
You can run the Qualys Lab SSL Test at: https://www.ssllabs.com/ssltest/index.html. On the test report, Java clients for JDK7 and JDK8 must pass. You will need to fix your wildcard CN certificate if you see the following errors in your report,
if you running Apache, you can address this issue by insuring the correct site names are contained within the Virtual Host configuration and including a ServerName and ServerAlias directived inside your Apache VirtualHost
Following is an article from Qualys Lab explains the issue: