For reasons I don't understand, Safari fails (intermittently but consistently) to connect to our rails app (static front end and api back end) on our QA infrastructure. (I'm going to write another question about that.)
For now, one thing that is confusing me is that Safari (in general) never seems to show the OPTIONS (preflight) requests that the other browsers (Chrome and Firefox) plainly show in their XHR networking list (in Developer Tools). I only ever see POST and GET requests, etc., never any OPTION requests.
Is Safari making them and just not showing them? Safari seems to do fine against our DEMO and PROD infrastructures (which have a slightly different set up) so I'm tempted to assume this is just a difference in their Developer Tools rather than the indication that something is wrong.