You should configure your Rails application correctly for production. Right now it seems like it's considering all requests as local and returning the Rails exception page to me.
Absolutely. I'm talking about things that should 404 are actually raising exceptions. E.g. https://feedi.me/popular. I hit this link by mistake but that should return a 404 and not the exception page from Rails.
This generally happens because config.consider_all_requests_local is set to true in production env. By default it should only be true in development and test.