I implemented CloudFlare recently for several Rails apps I host on Heroku. Just this week a couple users have reported being sent to a “Welcome to Nginx” page or a 503 error page when trying to access these apps. We have tried for a couple days but cannot reliably recreate the problem. Sometimes clearing browser cookies fixes the problem and sometimes it seems to make it worse.
Internet searches and searching CloudFlare documentation hasn’t produced any good information - at least that we can find. Has anyone experienced anything like this? Thanks in advance!