Api queries to restbase mobile-sections from iOS/Safari doesn't work when the page is a redirect, since the browser sends an Accept-Encoding header after the 302 but that is not allowed by the cors Access-Control-Allow-Headers which only reports Accept as a valid header to set.
As a result the browser fails to make the request.
See http://jsbin.com/cuqula/edit?js,output for broken example.
In Safari < 10 the redirect is being preflighted with an OPTIONS request with Access-Control-Request-Headers: accept-encoding, origin, accept-language but restbase responds with Access-Control-Allow-Headers: accept, content-type, which causes the request to fail (see wikimedia/restbase/lib/security_response_header_filter.js#L62)
- Temporarily use a CORS proxy for Safari browsers
- Add the Safari sent headers to Access-Control-Allow-Headers in restbase