PWA, Firebase and Google login: Unable to process request

I'm trying to make a PWA app for android out of my existing Angular app, where I use Firebase authentication (Google login - Sign in with popup). Everything works fine on my web app, but when I try to sign in on PWA on android, I can't login with Google. (BTW, Sign-in with password and username works fine.) It stops working after clicking on e-mail address within Google Sign-In popup. Page is blank. If I copy URL into the "normal" web browser, page is blank with the following error: Unable to process request due to missing initial state. This may happen if browser sessionStorage is inaccessible or accidentally cleared. What does this mean? Since is my first PWA app, I left the settings of 'webmanifest' and service worker config file as they were when created with ng add @angular/pwa.