OIDC configuration not available when connecting behind corporate proxy with authentication

[RenoV8-tls]

Hello everyone,

I am trying to deploy Dependency-Track behind a corporate proxy that requires authentication. Dependency-Track is able to download CVE data from https://nvd.nist.gov/ successfully through the proxy, using the ALPINE_PROXY_<...> environment variables.
However, when it tries to fetch the OIDC configuration, I encounter a 407 Proxy Authentication Required error.

I found a similar issue (#1940 on GitHub) but it doesn't specifically mention proxy authentication.

Does anyone know why this happens?
Should I create a new issue for it?

Thanks for your help!