JIRA integration with JIRA OnDemand may not work with @ symbol in username

Zendesk issue: https://gitlab.zendesk.com/agent/tickets/14927

A customer reports that they were unable to get JIRA integration to work when they used an email address as a username. Email addresses are the default sign in for JIRA OnDemand. I tested this with a local JIRA instance and created a user with an @ symbol in the username. I was able to use our integration successfully.

Is there something different about JIRA OnDemand that causes this issue? Can we set up an OnDemand account to test? Based on outcome, file a bug or write documentation as appropriate.

cc/ @axil FYI