Executing a curl in PlayFab for my title in development mode, the server is returning the following headers:
< HTTP/2 200 < date: Wed, 15 Sep 2021 10:11:45 GMT < content-type: application/json < content-length: 61 < server: nginx/1.14.0 (Ubuntu) < access-control-allow-credentials: true < access-control-allow-headers: Content-Type, Content-Encoding, X-Authentication, X-Authorization, X-PlayFabSDK, X-ReportErrorAsSuccess, X-SecretKey, X-EntityToken, Authorization, x-ms-app, x-ms-client-request-id, x-ms-user-id < access-control-allow-methods: GET, POST < access-control-allow-origin: * < x-requestid: 1-6141c6e1-6c86da9e3c8028586bc2da0e < x-tracecontext-traceid: 9fe5df86ce119b47917be86ce966d6ad
As you can see, the request is answered by a Ubuntu running nginx/1.14.0. Doing a quick search [1], this version was deprecated around 2019-05-30.
1: https://nginx.org/en/download.html?_ga=2.63802479.1104033220.1558590074-1880788572.1558590074
