ionic/angular pwa doesn't bootstrap when launched from home screen

I followed these guides to add pwa support and host my ionic v4 app:

• https://www.joshmorony.com/create-a-pwa-with-angular-service-workers-in-ionic-4/
• https://www.joshmorony.com/hosting-an-ionic-pwa-with-firebase-hosting/

The app loads fine in Safari, and I can also add the app to my home screen (ios). However, from the home screen, the app does not bootstrap when launched.

If I go to Safari DevTools and reload the page after launch, the app is just fine.

I'm also not exactly clear on the minimum requirements for a pwa. My app loads the google maps javascript api on launch, so it doesn't really work without a network connection. I'm not sure if that is part of the problem or not.

ionic info

Ionic:

   ionic (Ionic CLI)             : 4.3.1 (/Users/m/.nvm/versions/node/v8.9.4/lib/node_modules/ionic)
   Ionic Framework               : @ionic/angular 4.0.0-beta.15
   @angular-devkit/build-angular : 0.8.7
   @angular-devkit/schematics    : 0.8.7
   @angular/cli                  : 7.0.5
   @ionic/angular-toolkit        : 1.1.0

Capacitor:

   capacitor (Capacitor CLI) : 1.0.0-beta.7
   @capacitor/core           : 1.0.0-beta.7

Cordova:

   cordova (Cordova CLI) : 8.0.0
   Cordova Platforms     : ios 4.5.5
   Cordova Plugins       : cordova-plugin-ionic-keyboard 2.1.3, cordova-plugin-ionic-webview 2.1.4, (and 10 other plugins)

System:

   ios-deploy : 2.0.0
   NodeJS     : v8.9.4 (/Users/m/.nvm/versions/node/v8.9.4/bin/node)
   npm        : 6.4.1
   OS         : macOS High Sierra
   Xcode      : Xcode 10.0 Build version 10A255

on reload of the pwa app from DevTools, I see this error:

[Error] ERROR
Error: Uncaught (in promise): SecurityError: MIME Type is not a JavaScript MIME type
    vt (main.0c301dd161ca4cc6d73d.js:1:123807)
    handleError (main.0c301dd161ca4cc6d73d.js:1:124014)
    next (main.0c301dd161ca4cc6d73d.js:1:139466)
    (anonymous function) (main.0c301dd161ca4cc6d73d.js:1:131304)
    __tryOrUnsub (main.0c301dd161ca4cc6d73d.js:1:247187)
    next (main.0c301dd161ca4cc6d73d.js:1:246340)
    _next (main.0c301dd161ca4cc6d73d.js:1:245384)
    next (main.0c301dd161ca4cc6d73d.js:1:245056)
    next (main.0c301dd161ca4cc6d73d.js:1:272048)
    emit (main.0c301dd161ca4cc6d73d.js:1:131085)
    run (polyfills.0548e3ebf74d8c45f01b.js:1:2461)
    onHandleError (main.0c301dd161ca4cc6d73d.js:1:133065)
    runGuarded (polyfills.0548e3ebf74d8c45f01b.js:1:2721)
    e (polyfills.0548e3ebf74d8c45f01b.js:1:11589)
    microtaskDrainDone (polyfills.0548e3ebf74d8c45f01b.js:1:11638)
    d (polyfills.0548e3ebf74d8c45f01b.js:1:10261)
    promiseReactionJob

It seems like it should be related to Angular ServiceWorkers + MIME type error, but I'm using ionic build --prod; firebase deploy and the build output is all minimized.

Here's the network log when I launch the App from Home screen:

And here's what it looks like after I click reload in DevTools

from ionic/angular pwa doesn't bootstrap when launched from home screen