Response: 502 for https://gitlab.com/gitlab-org/gitlab-ce/graphs/master/ci

I was navigating normally until I got a 502 for https://gitlab.com/gitlab-org/gitlab-ce/graphs/master/ci

I already have the page loaded, then tried to reach out another tab "Continuous Integration"=> page didn't load and returned to me a 502.

Well, after that I hit the back button and got the JSON file - as in this issue: https://gitlab.com/gitlab-org/gitlab-ce/issues/17365

cc/ @stanhu @MrChrisW