By default the homepage of your Progressive Web App will always display the latest posts from your blog. For this reason, if you have set your front page to display a static custom page (screenshot below), the PWA will not properly display it in the homepage.
The solution here is quite simple. You don't need to change your front page, just follow these steps:
1. Go to Advanced Settings screen of WP-PWA plugin from your WordPress dashboard. 2. In the settings box, go to Force Frontpage and check the box.
3. Click on Save changes.
That's it. Now the homepage of the PWA will display again the latest posts from your blog.