I added CORS annotations to my chart, but the CORS headers are only being returned from OPTIONS requests. GET requests are missing the headers, which causes errors in the browser.

Annotations added:
nginx.ingress.kubernetes.io/enable-cors: "true"
nginx.ingress.kubernetes.io/cors-allow-origin: "*"
nginx.ingress.kubernetes.io/cors-allow-credentials: "false"
nginx.ingress.kubernetes.io/cors-allow-headers: (...headers)

OPTIONS requests to (my API URL) are working as I expect, with the CORS headers being returned.
GET requests to (my API URL) are not behaving as expected, with no CORS headers in the response at all.

I was expecting that all allowed request methods would be returned with CORS response headers e.g.:
Access-Control-Allow-Origin: *
Access-Control-Allow-Headers: (...headers)
Access-Control-Allow-Methods: ...
Etc.

Without these on the GET request the browser seems to give a CORS error for every request, making the API unusable.

I considered applying the individual headers I want manually using snippets but it seems like this configuration should be possible using the CORS annotations? Any help much appreciated.