MDB Modal Dynamic don't use already existing data servi

I used Modal from ngx-bootstrap and I try to switch to MDB Modal. I use Modal with Dynamic Modal Options.

Before I use (with private modalService: BsModalService):

this.modal = this.modalService.show(AppModalFormComponent, { initialState: { form: this }, backdrop: 'static' });

Now (with private modalService: MDBModalService):

this.modal = this.modalService.show(AppModalFormComponent, {
          backdrop: true,
          keyboard: true,
          focus: true,
          show: false,
          ignoreBackdropClick: false,
          class: '',
          containerClass: '',
          animated: true,
          data: {
            form: this,
          }
        });

In both case, modal is showing via AppModalFormComponent. In this component, I use a service (FormService with a console log in the constructor of the service). In the first case (ngx-bootstrap), the contructor service is not showing (because already initialized) and I can access to service data. In the second one (MDB), service constructor is showing (while it is already initialized) and data is undefined. Why ?