rxjs-compat subscribe have no effect

[Frennetix]

I use a library ng2-bs3-modal and after upgrading my project to version 6.x.x the subscribe have no effect:

<bs-modal #modal>
  ...
</bs-modal>

@ViewChild('modal')
modal1: BsModalComponent;

this.modal1.onClose.subscribe(
  () => {
    console.log('close');
  }
)

Repo to reproduce:
https://github.com/Frennetix/rxjs6-ng2-bs3-modal

[Frennetix]

I'll add that:
this.modal1.onOpen.emit();

trigger the subscribe()

[whiteinge]

This repo is for the Rx 4 version. You want https://github.com/ReactiveX/rxjs instead.