InAppBrowser sometimes empty/white


#1

Im working on a project where I make much use of the InAppBrowser to view different documents (PDF, DOC, DOCX). I do this with the help och docs.google.com, and the documents are stored in firebase-storage.
Most of the time it works great on my Android device! But sometimes all i get is a white screen, and i have to press the back button to close the InAppBrowser and then re-open it to show the document.

When remotely debugging this strange behaviour in Chrome developer tools i see that the loadstart and loadstop events are called appropriately:

When i look at the HTML in the empty/white InAppBrowser i see empty <body>-tags:

The code im using to open the InAppBrowser:

import { Injectable } from '@angular/core';
import { Platform } from 'ionic-angular';
import { InAppBrowser, InAppBrowserObject } from '@ionic-native/in-app-browser';
import { ScreenOrientation } from '@ionic-native/screen-orientation';
import { LoaderService } from './loader-service';
import * as firebase from 'firebase';

@Injectable()
export class FirebaseStorageService{
    browserOptions: string;
    browser: InAppBrowserObject;

    constructor(
        private iab: InAppBrowser,
        private loaderService:LoaderService,
        private platform: Platform,
        private screenOrientation: ScreenOrientation
    ){
        this.browserOptions = 'zoom=no,location=no,useWideViewPort=no,hidden=yes,enableViewportScale=yes';
    }

    viewPdf(path: string, loadText?:string):Promise<any>{
        this.showLoader(loadText);
        return new Promise<any>((resolve, reject) => {
            firebase.storage().ref().child(path).getDownloadURL().then(url => {
                let newURL = 'https://docs.google.com/gview?&url=' + encodeURIComponent(url);
                this.startBrowser(newURL);
                resolve();
            })
            .catch(err => {
                if(this.platform.is('cordova')){
                    this.loaderService.dismissLoader();
                }
                reject(err);
            });
        })
    }

    private startBrowser(path:string):void{
        this.browser = this.iab.create(path, '_blank', this.browserOptions);
        if(this.platform.is('cordova')){
            this.handleBrowserSubscriptions();
            this.screenOrientation.unlock();
        }
    }

    private handleBrowserSubscriptions():void{
        let stopSub = this.browser.on('loadstop').subscribe(event => {
            console.log('loadstop', event)
            this.loaderService.dismissLoader();
            this.browser.show();
            stopSub.unsubscribe();
            errorSub.unsubscribe();
        });

        let exitSub = this.browser.on('exit').subscribe(event => {
            console.log('exit:',event)
            this.loaderService.dismissLoader();
            exitSub.unsubscribe();
            this.browser.close();
            this.screenOrientation.lock(this.screenOrientation.ORIENTATIONS.PORTRAIT);
        });

        let errorSub = this.browser.on('loaderror').subscribe(event => {
            console.log('loaderror', event)
            this.loaderService.dismissLoader();
            this.browser.close();
            this.screenOrientation.lock(this.screenOrientation.ORIENTATIONS.PORTRAIT);
            stopSub.unsubscribe();
            errorSub.unsubscribe();
        });

        let startSub = this.browser.on('loadstart').subscribe(event => {
            console.log('loadstart', event);
        })
    }
}

Ionic info:

Cordova CLI: 7.0.1
Ionic Framework Version: 3.2.0
Ionic CLI Version: 2.2.1
Ionic App Lib Version: 2.2.0
Ionic App Scripts Version: 1.3.7
ios-deploy version: Not installed
ios-sim version: Not installed
OS: Windows 10
Node Version: v6.9.4
Xcode version: Not installed

Has anyone else experienced this, or does anyone know how to resolve this?