Good point regarding the http / TLS. So you doubt it will be Azure services rejecting calls (via a 403) from topomap.co.nz because of the 2 different SSL certificates present for topomap.co.nz?
Regarding the proxy code, I’m using this (configured to allow proxy’ing to anything) …
There’s a lot of extra stuff in there I don’t need, but I’ve stepped through the code locally and can see it’s just re-issuing a basic GET request for these calls by-passing all the more advanced logic.