ASP.NET Core 6.0 razor web pages: Serilog don't log within Model pages

Question

This one is driving me crazy and I don't see the reason. Maybe one of you can help me?

I'm trying to activate logging with Serilog within my Razor web. Here is my code in Program.cs:

var builder = WebApplication.CreateBuilder(args);

// enabling logging
// Filter to exclude access to static content
builder.Logging.ClearProviders();
builder.Host.UseSerilog((ctx, config) =>
{
  config
    .ReadFrom.Configuration(ctx.Configuration);
});

// doing all the other stuff

var app = builder.Build();

app.UseSerilogRequestLogging();

// doing all the other stuff

Here is my serilog config from appsettings.json:

"Serilog": {
    "Using": [ "Serilog.Sinks.File", "Serilog.Sinks.Console" ],
    "MinimumLevel": {
      "Default": "Information",
      "Override": {
        "Microsoft": "Warning",
        "System": "Warning"
      }
    },
    "WriteTo": [
      {
        "Name": "Console"
      },
      {
        "Name": "File",
        "Args": {
          "path": "logs/web_.log",
          "outputTemplate": "{Timestamp:o} [{Level:u3}] ({SourceContext}) {Message}{NewLine}{Exception}",
          "rollingInterval": "Day",
          "retainedFileCountLimit": 7
        }
      }
    ],
    "Enrich": [ "FromLogContext", "WithThreadId", "WithMachineName" ]
}

Now the crazy point here is, when I am doing this in a custom service class it is working:

public class UserRoleHandler : IUserRoleHandler
{
    private ILogger<UserRoleHandler> _logger;

    public UserRoleHandler(ILogger<UserRoleHandler> logger)
    {
        _logger = logger;
    }

    private void _getData()
    {
        _logger.LogInformation("start checking group membership.");
    }
}

But doing pretty the same in a model class doesn't work.

public class CreateModel : PageModel
{
    private ILogger<CreateModel> _logger;
 
    public CreateModel(MyContext context, ILogger<CreateModel> logger)
    {
        _logger = logger;
        _logger.LogInformation("Model created.");
    }

    public async Task<IActionResult> OnPostAsync()
    {
        _logger.LogInformation("Start saving my data.");
    } 
}

While logging from my own service calls is working, nothing is logging when I do this from my Page Model, nether on console nor in the file.

I've tried to change my settings, to check whether they are applied, I can see impact when changing.

I also removed Serilog and the "normal" log writes my output to console.