Why is controllerbase.challenge returning a 200 instead of a 302 reidirect

I am using controllerbase.challenge in asp.net core to authenticate my web application against an oidc provider. In all but one deployment environments, i see the appropriate redirect to the oidc provider when i hit my mvc endpoint where I am invoking controllerbase.challenge.

What could be an explanation for this? Everywhere else I see a 302 to the oidc provider except in the problematic environment where I see a 200 ok response

    public IActionResult Authenticate()
    {
        return Challenge(new AuthenticationProperties { RedirectUri = "/" }, OpenIdConnectDefaults.AuthenticationScheme);
    }