gRPC service suddenly returns 401

I'm hosting a Blazor app that uses gRPC with Microsoft Identity in IIS. After starting the app, everything is working as expected and gRPC is responding to all of my requests, but after a day the gRPC service return 401 status code even I can use other pages of Blazor app that are annotated by [Authorize] attribute.

I can solve the problem by recycling app pool.

```
[Authorize]
public class GreeterService : Greeter.GreeterBase
{
private readonly ILogger _logger;
public GreeterService(ILogger logger)
{
_logger = logger;
}

public override Task SayHello(HelloRequest request, ServerCallContext context)
{
return Task.FromResult(new HelloReply
{
Message = "Hello " + request.Name
});
}
}
```

```
builder.Services
.AddGrpcClient(options => options.Address = new Uri(builder.HostEnvironment.BaseAddress))
.ConfigurePrimaryHttpMessageHandler(services =>
{
var baseAddressMessageHandler = services.GetRequiredService();
baseAddressMessageHandler.InnerHandler = new HttpClientHandler();

return new GrpcWebHandler(baseAddressMessageHandler);
});
```