I was unable to reproduce this issue on my machine using Opera. If you can consistently reproduce this, please include a little more information like the Operating System and version of Opera. Be sure to also try multiple other issues to narrow down if this one issue is causing your troubles. Also, please let us know if you can/can't reproduce this issue on any other browser on your machine.
I cannot reproduce this issue with the same settings (enabled do not track). If you're using any other third party add blockers or tracker blockers, please try to disable them and see if that allows your request to process.
As we haven't heard back from you in a week about this issue, we're going to mark it as closed. If you still have issues with this after you've disabled all third-party extensions, please raise a support request to support.atlassian.com so we can help you privately.