Handle method are executed twice in INotificationHandler in a specific scenario.

I have a question regarding the behavior of the Handle method in INotificationHandler in a specific scenario.

I have an ApprovedEventHandler.cs class which is a NotificationHandler that sends email notifications and uses a generic type for reusability. Here is the code snippet:

public abstract class DomainEvent: INotification
{
    protected DomainEvent()
    {
        DateOccurred = DateTimeOffset.UtcNow;
    }
    public bool IsPublished { get; set; }
    public DateTimeOffset DateOccurred { get; protected set; }
}
public  class ApprovedEvent<T>: DomainEvent
{
    public ApprovedEvent(T entity)
    {
        Entity = entity;
    }

    public T Entity { get; }
}
public class DomainEventNotification<TDomainEvent> : INotification where TDomainEvent : DomainEvent
{
    public DomainEventNotification(TDomainEvent domainEvent)
    {
        DomainEvent = domainEvent;
    }

    public TDomainEvent DomainEvent { get; }
}

public class ApprovedEventHandler<T> : INotificationHandler<DomainEventNotification<ApprovedEvent<T>>> where T : AuditableEntity
{

    public ApprovedEventHandler()
    {
    }
    public async Task Handle(DomainEventNotification<ApprovedEvent<T>> notification, CancellationToken cancellationToken)
    {
        var domainEvent = notification.DomainEvent;
         
    }
}

The issue I am encountering is that when I exclude this ApprovedEventHandler.cs class from the project, all other NotificationHandlers are executed twice (subscribed twice) after compiling and adding the class back in.

I would appreciate it if someone could explain to me why this is happening. Although I have found a workaround for this problem, I am still curious to understand the underlying principle. Thank you.

public class AccessRequestCreatedEvent: DomainEvent
{
    public AccessRequestCreatedEvent(AccessRequest item)
    {
        Item = item;

    }

    public AccessRequest Item { get; }
}
public class AccessRequestCreatedEventHandler: INotificationHandler<AccessRequestCreatedEvent>
{
   
    public AccessRequestCreatedEventHandler(
      
            )
    {
        
    }
    public async Task Handle(AccessRequestCreatedEventnotification, CancellationToken cancellationToken)
    {
        var request = notification.Item;

    }
}

[MichaelHochriegl]

Here is the issue on dotnet side: https://github.com/dotnet/runtime/issues/87017

In this issue there are two MRs that fix that problem: https://github.com/dotnet/runtime/pull/80410 https://github.com/dotnet/runtime/pull/52035

[jbogard]

My last PR for Microsoft DI was open for 5 years (literally) before merging so…good luck lol.