Root problems in cshtml .NET 9

Question

I've a server app with C# and Razor pages.

In order to integrate with a shibboleth server, I exposed a root through a cshtml page (not authenticated) that then redirects to another razor page.

I upgraded the app from .NET7 to .NET 9 and the page can no longer be reached (HTTP error 404).

@page "/entryPointcshtml"

@namespace ...

@using I....

@using Microsoft.AspNetCore.DataProtection

@inject IDataProtectionProvider _dataProtectionProvider

*@addTagHelper , Microsoft.AspNetCore.Mvc.TagHelpers

<h1>Redirect in progress</h1>

The page simply reads the headers and from the request and then redirects.

However, the server is no longer able to expose the root at runtime. Should I force something in the program.cs?

Any other options?