Blazor Web Assembly (stand alone) - [Authorize] Attribute not recognising roles straight after login

public override async Task<AuthenticationState> GetAuthenticationStateAsync() {
    _logger.LogInformation("GetAuthenticationStateAsync() called");
    // ... snip ...
}

public override async Task<AuthenticationState> GetAuthenticationStateAsync() {
    _logger.LogInformation("GetAuthenticationStateAsync() called");
    // ... snip ...
}

public override async Task<AuthenticationState> GetAuthenticationStateAsync() {
    _logger.LogInformation("### GetAuthenticationStateAsync() called");
    var authState = await base.GetAuthenticationStateAsync();
    var user = authState.User;
    if (user.Identities.Any(x => x.AuthenticationType == "TemplateProject-api"))
    {
        _logger.LogInformation("### Found custom identity - returning early");
        return (await Task.FromResult(new AuthenticationState(user)));
    }

    
    _logger.LogInformation("### We are authenticated: {Authed}", user.Identity?.IsAuthenticated);
    
    List<Claim> claims = []; 
    if (user.Identity?.IsAuthenticated ?? false)
    {
        // snip - fetching `profile` from my API and populating `claims` with my custom roles
    }

    var state = Task.FromResult(new AuthenticationState(user));
    if (claims.Count != 0)
    {
        _logger.LogInformation("### Adding new claims identity to principal: {Claims}", JsonSerializer.Serialize(claims.Select(x => new {x.Type, x.Value})));
        user.AddIdentity(new ClaimsIdentity(claims, "TemplateProject-api"));
        state = Task.FromResult(new AuthenticationState(user));
        _logger.LogInformation("### NotifyAuthenticationStateChanged");
        NotifyAuthenticationStateChanged(state);
    }
    
    _logger.LogInformation("### DONE");
    return (await state);
}

public override async Task<AuthenticationState> GetAuthenticationStateAsync() {
    _logger.LogInformation("### GetAuthenticationStateAsync() called");
    var authState = await base.GetAuthenticationStateAsync();
    var user = authState.User;
    if (user.Identities.Any(x => x.AuthenticationType == "TemplateProject-api"))
    {
        _logger.LogInformation("### Found custom identity - returning early");
        return (await Task.FromResult(new AuthenticationState(user)));
    }

    
    _logger.LogInformation("### We are authenticated: {Authed}", user.Identity?.IsAuthenticated);
    
    List<Claim> claims = []; 
    if (user.Identity?.IsAuthenticated ?? false)
    {
        // snip - fetching `profile` from my API and populating `claims` with my custom roles
    }

    var state = Task.FromResult(new AuthenticationState(user));
    if (claims.Count != 0)
    {
        _logger.LogInformation("### Adding new claims identity to principal: {Claims}", JsonSerializer.Serialize(claims.Select(x => new {x.Type, x.Value})));
        user.AddIdentity(new ClaimsIdentity(claims, "TemplateProject-api"));
        state = Task.FromResult(new AuthenticationState(user));
        _logger.LogInformation("### NotifyAuthenticationStateChanged");
        NotifyAuthenticationStateChanged(state);
    }
    
    _logger.LogInformation("### DONE");
    return (await state);
}