Hi Charlie,
this is a known issue, we already have a Jira issue for that please feel free to upvote, comment or watch this issue:
https://k15t.jira.com/browse/VPRT-885 ( please
sign up for upvoting, commenting or watching the issue )
here you will also find some workarounds to solve this problem. The simplest way would be to restrict the Confluence UI to anonymous users, so they get redirected to the Viewport view.
Let me know if that is solving your problem.
Thanks and have a nice day.
Best,
Steffen