Why does /Account/Login briefly render then disappear in a .NET 10 Blazor Web App using InteractiveServer and ASP.NET Identity? #65652
Description
Is there an existing issue for this?
- I have searched the existing issues
Describe the bug
I am building a .NET 10 Blazor Web App (Visual Studio 2026 template) using:
- Interactive Server components
- ASP.NET Core Identity
- EF Core with SQL Server
The application runs normally, but I am having problems implementing a login page.
Problem
When navigating to:
/Account/Login
the login page briefly renders and then disappears (appears to redirect or render NotFound).
The UI "blinks" and the login form cannot be used.
This behavior only occurs when the application becomes interactive.
If interactivity is disabled, the login page renders normally.
Project configuration
Program.cs:
builder.Services.AddRazorComponents()
.AddInteractiveServerComponents();
builder.Services.AddIdentityCore<ApplicationUser>()
.AddEntityFrameworkStores<NexaPlatformDbContext>()
.AddSignInManager()
.AddDefaultTokenProviders();
app.UseAuthentication();
app.UseAuthorization();
app.MapRazorComponents<App>()
.AddInteractiveServerRenderMode();Router configuration
Routes.razor:
<CascadingAuthenticationState>
<Router AppAssembly="@typeof(Program).Assembly">
<Found Context="routeData">
<AuthorizeRouteView RouteData="@routeData"
DefaultLayout="@typeof(MainLayout)">
<NotAuthorized>
<RedirectToLogin />
</NotAuthorized>
</AuthorizeRouteView>
</Found>
<NotFound>
<p>Not Found</p>
</NotFound>
</Router>
</CascadingAuthenticationState>Login component
@page "/Account/Login"
@attribute [AllowAnonymous]
<form method="post" action="/account/login">
<AntiforgeryToken />
<input type="hidden" name="returnUrl" value="@ReturnUrl" />
<div>
<label>Email</label>
<input name="email" />
</div>
<div>
<label>Password</label>
<input type="password" name="password" />
</div>
<button type="submit">Sign in</button>
</form>
@code {
[SupplyParameterFromQuery(Name = "returnUrl")]
public string? ReturnUrlQuery { get; set; }
private string ReturnUrl => string.IsNullOrWhiteSpace(ReturnUrlQuery) ? "/" : ReturnUrlQuery!;
}Things I have already checked
- Only one component declares
@page "/Account/Login" - [AllowAnonymous] is applied to the login page
- No global [Authorize] attributes exist in _Imports.razor
- prerendering disabled (InteractiveServerRenderMode(prerender:false))
- duplicate routes removed
- minimal API login endpoint works correctly
Expected Behavior
When I click login, i should be taken to login page and be able to login without it appearing for a second then saying not found.
Steps To Reproduce
No response
Exceptions (if any)
No response
.NET Version
No response
Anything else?
No response