Custom ITelemetryInitializer in azure function .Net Core 3.1 does not work

Custom ITelemetryInitializer in azure function .Net Core 3.1 does not work.

I’ve implemented a custom ITelemetryInitializer and injected using Dependency injection as Singleton but Initialize method of ITelemetryInitializer of custom class is not hit.

Repro steps

1. Created a new .Net core 3.1 Azure function with Http binding.
2. Installed Microsoft.Azure.Functions.Extensions 1.0.0 package
3. Installed Microsoft.ApplicatoinInsights 2.13.1 package

Created a new Custom ITelemetryInitializer class

public class MyCustomTelemetryInitializer : ITelemetryInitializer
{
    public MyCustomTelemetryInitializer()
    {
    }

    public void Initialize(ITelemetry telemetry)
    {
        if (telemetry == null)
        {
            return;
        }

        telemetry.Context.GlobalProperties["SomePropertyName"] = "SomePropertyValue";
    }
}

Added Startup implemenation

[assembly: FunctionsStartup(typeof(SomeNamespace.Startup))]

namespace SomeNamespace
{
    public class Startup : FunctionsStartup
    {
        public override void Configure(IFunctionsHostBuilder builder)
        {
            builder.Services.AddSingleton<ITelemetryInitializer, MyCustomTelemetryInitializer>();

        }
    }
}

The configure method is hit (If I hit the breakpoint) but breakpoint at MyCustomTelemetryInitializer is never hit and due to that the custom telemetry properties are not injected.

Expected behavior

The custom properties injected by MyCustomTelemetryInitializer should be logged.

Actual behavior

The custom properties injected by MyCustomTelemetryInitializer are NOT being logged.

Known workarounds

NA

Related information

1. .Net Core : 3.1
2. Microsoft.NET.Sdk.Functions - 3.0.1
3. Microsoft.Azure.Functions.Extensions 1.0.0
4. Microsoft.ApplicatoinInsights 2.13.1

Tried downgrading the Microsoft.ApplicatoinInsights to 2.11.0 but still did not work.

[dongup]

I have the same issue, and I am using Microsoft.NET.Sdk.Functions 4.0.1. Please help me, thank you.

[KamranMammadov]

Any updates? .Net 6.0 isolated