In the old issue view, click on the 'Vote for this issue' link
There is a known issue JSDSERVER-1367
That is a redirect loop that keeps directing you back to the Portal rather than following the link to a Jira Issue. Please go and vote on the above issue to let Atlassian know you are having this problem. Currently, there is no known workaround.
If you have logged into our Portal for support you have access to Jira features as a Jira user. Just log in to our portal and then navigate from there to the issue that your ticket has been escalated to.