[Android] things disapear after showing a interstitial ad

After closing an interstitial ad some of the buttons and elements in the app disapear.

Loading the ad and events work correctly:
this.ad.onAdEvent((event, error, data) => { switch (event) { case AdEventType.LOADED: console.log('ad loaded'); this.ad.show(); break; case AdEventType.CLOSED: this.routerExtensions.navigate(['postcard-viewer', Constants.Modules.PostCardEditor.result]); break; case AdEventType.OPENED: break; case AdEventType.IMPRESSION: break; case AdEventType.FAILED_TO_SHOW_FULL_SCREEN_CONTENT: console.error('InterstitialAd failed to load:', error); this.routerExtensions.navigate(['postcard-viewer', Constants.Modules.PostCardEditor.result]); break; } }); this.ad.load();

Showing the ad also works correctly.

Once the ad is closed, some buttons and elements are not shown anymore for example:

<Button *ngIf="stateService.freeCard && !loadingQuota && quotaAvailable" [isEnabled]="!showspinner" class="pcc-dark-button send-button" [text]="'viewer.backside.free-send' | translate" actionKey="SEND" (tap)="onSendClick()"> </Button>

インタースティシャル広告のイベントハンドラーと issue に示されている CLOSED のナビゲーションパスから始め、Android で広告を閉じて問題を再現します。ナビゲーション前後のビューの状態を比較します。広告を閉じた後もボタンやその他の要素が表示されたままなら完了です。