Modal not rendering template in multiple tabs

IMPORTANT: I could not reproduce the issue using plnkr, so I attached a small zip file ngx-modialog-demo.zip

I'm submitting a bug
Do you want to request a feature or report a bug? Report a bug.
What is the current behavior? If I open a modal in two more more tabs from a BroadcastChannel onMessage event, only one of the modals is opened and the rest of the tabs have a thin line (ie the modal template is not rendered). The modal html looks like the following

<modal-overlay style="position: fixed; top: 0px; left: 0px; bottom: 0px; right: 0px; z-index: 1500;">
   <div>
      <!---->
      <css-backdrop class="modal-backdrop fade show"></css-backdrop>
      <bs-modal-container class="modal fade show" role="dialog" style="position: absolute; display: block" tabindex="-1">
         <div class="modal-dialog modal-lg" ng-reflect-ng-class="modal-dialog">
            <div class="modal-content" overlaydialogboundary="" role="document" style="display:block">
               <!----> <!---->
            </div>
         </div>
      </bs-modal-container>
   </div>
   <!---->
</modal-overlay>

If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem via

Open ngx-modialog-demo.zip. Or choose any component in an existing app and use the following code


export class AppComponent implements OnInit, OnDestroy {
title = 'ngx-modialog-demo';
broadCastChannel: BroadcastChannel;

constructor(public modal: Modal) { }

ngOnDestroy(): void {
this.broadCastChannel.close();
}
ngOnInit(): void {
this.broadCastChannel = new BroadcastChannel('ngx-modialog-demo');
this.broadCastChannel.onmessage = ((_ev: MessageEvent) => {
  const dialogRef = this.modal.alert()
    .size('lg')
    .showClose(true)
    .title('A simple Alert style modal window')
    .body(`
        <h4>Alert is a classic (title/body/footer) 1 button modal window that 
        does not block.</h4>
        <b>Configuration:</b>
        <ul>
            <li>Non blocking (click anywhere outside to dismiss)</li>
            <li>Size large</li>
            <li>Dismissed with default keyboard key (ESC)</li>
            <li>Close wth button click</li>
            <li>HTML content</li>
        </ul>`)
    .open();
  dialogRef.result.then(result => { });
});

setTimeout(() => {
  this.broadCastChannel.postMessage({});
}, 2000);

}
}

2. `npm install` (ie  Restore modules)
2. Run the app (`ng serve --port 1234`) and open it in two or more tabs.

* **What is the expected behavior?**
You should see the modal in all opened tabs 2 seconds after the tab is opened.

* **What is the motivation / use case for changing the behavior?**
I expect the modal to be shown in all tabs instead of a thin line.

* **Please tell us about your environment:**
    * `ng --version`

Angular CLI: 7.3.0
Node: 8.12.0
OS: win32 x64
Angular: 7.2.3
... animations, common, compiler, compiler-cli, core, forms
... language-service, platform-browser, platform-browser-dynamic
... router

Package                           Version
-----------------------------------------------------------
@angular-devkit/architect         0.13.0
@angular-devkit/build-angular     0.13.0
@angular-devkit/build-optimizer   0.13.0
@angular-devkit/build-webpack     0.13.0
@angular-devkit/core              7.3.0
@angular-devkit/schematics        7.3.0
@angular/cli                      7.3.0
@ngtools/webpack                  7.3.0
@schematics/angular               7.3.0
@schematics/update                0.13.0
rxjs                              6.3.3
typescript                        3.2.2
webpack                           4.29.0
```

NOTE: I was able to reproduce the issue in Angular 4.

Browser: [Chrome XX | Firefox XX ]
Other information (e.g. detailed explanation, stacktraces, related issues, suggestions how to fix, links for us to have context, eg. stackoverflow, gitter, etc) I could workaround this issue if I click anywhere on the overlay. So I put the following hack inside my components temporarily
```
setTimeout(() => {
  // Fixes the modal not rendering issue.
   document.body.click()
})
```

shlomiassaf / ngx-modialog

Modal not rendering template in multiple tabs #446