When doing a search on our discourse site, if I do a regular GET request to /search?q=my search it works fine. But if I use the search box and it submits the search request via an XHR GET request I get a 406 status return.
After some further testing with Postman I found that just adding an X-Requested-With: XMLHttpRequest header to the request breaks it. Remove that one header and it works fine. The server is behind Azure Front Door and bypassing it and hitting the server direct does not have this issue. Is nginx or search doing something special based on that header? Could being behind a reverse proxy interfere? Any idea how to fix?