Error Adding Addon

[Dev Pause]

Following the instructions here:

https://developer.atlassian.com/static/connect/docs/developing/cloud-installation.html

I've got my app added in the marketplace, listing set to private, and have created the token. When adding the addon however I get back the ominous error of:    

The add-on failed to install. Please try again later or contact the add-on vendor.

I've tested the descriptor via the descriptor validation tool and it comes up with no errors, and worked in the dev box so couldn't see anything obvious.

Nothing gets reported back to my app and not sure how to start to debug this. Any thoughts, ideas? I realize the info provided here maybe sparse, so please let me know what details I ought to provide to continue.

Update 1 -

In the audit log section for each attempted install I see:

Event category - user management
Change Summary - User updated
Changed Object - addon_udo-add-onRemote Crowd Directory

In the case that it can help here is a link to a marketplace descriptor:

https://marketplace.atlassian.com/files/1.0.0-AC/artifact/descriptor/49604097-7e98-4767-8ed3-aed1a593242b/atlassian-connect.json?access-token=01c265b1

Update 2

JIRA support was able to provide logs that show:

@4000000054f72c850b2e30b4 com.atlassian.upm.spi.PluginInstallException: Error contacting remote application [javax.net.ssl.SSLHandshakeException: General SSLEngine problem]

SSL Labs doesn't identify any further issues with our certificate configuration using their tool - https://www.ssllabs.com/ssltest/analyze.html?d=udojira.pause.ca&latest

So curious if anyone has any ideas as to what's going on with the SSL/HTTPS that triggers this error, as I don't encounter them in the dev environment. 

[Dev Pause · Accepted solution]

Issue seemed related to:

https://ecosystem.atlassian.net/browse/AC-1519