Cascade delete nested models in Mongoose

I am trying to remove all Entity related data using Mongoose middlewares.

I am calling entity.remove() and I am removing Contacts, Credentials, Accounts using EntitySchema.pre middleware.

   EntitySchema.pre('remove', async function (next) {
      this.contacts.forEach(c => Contact.remove({ _id: c._id }).exec());
      this.credentials.forEach(c => Credential.remove({ _id: c._id }).exec());
      this.accounts.forEach(a => Account.remove({_id: a._id}).exec());
      next();
    });

Except these I have Ledgers that are related with Accounts with acccountNumber property. I want to remove these Ledgers when Accounts removed with code below.

AccountSchema.pre('remove', async function (next) {
  await Ledger.deleteMany({accountNumber: this.accountNumber});
  next();
});

But they are not removing. I also put breakpoint to this part of code, it doesn't even passing through this part of code.

How can I deal in this situation?