I cannot connect to our Atlassian OnDeman Jira instance. From Jenkins > Manage Jenkins > Configure System, the following settings are configured:
URL: https://company.atlassian.net/
Link URL: <blank>
Use HTTP auth: false
Supports Wiki Notation: false
Record SCM Changes: true
Issue Pattern: <blank>
username: user
password: password
Connection timeout: 10
Visible for Group: <blank>
Visible for Project Role: <blank>
Add Timestamp to JIRA comments: false
Jira comments timestamp format: <blank>

When I hit "Validate Settings" I receive an ERROR link that gives me a java.net.SocketTimeoutException, stack trace is in the file attached.

Things I have tried:
1. Making sure Jenkins user can access URL from that server, works fine in web browser.
2. Changing proxy settings to configure as a no proxy host, both in jenkins and on server.
3. Increasing the value of connection Timeout, has no affect.
4. Falling back to the previously working Jira plugin. This just led to a new error.
5. Making sure rest is enabled, hitting /rest/api/latest/issue/TES-1 returns successful.

The last time that this was working for me was September 1, 2015, with jira plugin ver. 1.39 and whatever the latest OnDemand Jira instance was at the time. No configuration should have changed on Jenkins or Jira since then, just versions. Any suggestions for further troubleshooting would be greatly appreciated.