HTTP 203 Non-Authoritative Information means the request was successful but the response payload has been modified by a transforming proxy between the origin server and the client. The returned content may differ from the origin's 200 OK response.
A transparent proxy or CDN transformed the response body (e.g., image compression, content rewriting) before returning it.
A mobile content adaptation proxy modified the response for a different device format.
Request the resource directly from the origin to see the unmodified version.
curl -v --resolve example.com:443:ORIGIN_IP https://example.com/
The Via header identifies which proxy modified the response.
If the proxy modification is causing issues, access the origin directly or configure the proxy to pass through unmodified.