Blazor server with web api controller authenticate issue

I have a Blazor server app that I want to add a web api controller to that can be accessed from Postman and eventually other apps. The Blazor app needs authentication, but not the web api. I tried adding AllowAnonymous, but I am getting an authentication error calling it from Postman:

HTTP Error 401.2 - UnauthorizedYou are not authorized to view this page due to invalid authentication headers.

I suspect our security proxy is adding the headers:

Is it possible to host an unsecured (AllowAnonymous) web api inside an authenticated Blazor Server app?

Maybe I just need to craft my api call a certain way?

Controller:

[Route("api/[controller]")][ApiController][AllowAnonymous]public class ProfileController : ControllerBase{    [HttpGet("{year}", Name = "GetProfileResults")]    public async Task<IActionResult> GetProfileResults(int year)    {        var profileResults = repo.GetResults(year);        return Ok(profileResults);    }}