How to test offline

[tacman]

I have an app at https://pokemon.survos.com/ which I want to run offline. I've setup the offline page to app_index and preload it, but after loading (and installing) if I turn the network off and try to open the app, it says it's offline. Running pwa-bundle:1.3.x

    serviceworker:
        enabled: true
        src: "sw.js"
        skip_waiting: true
        workbox:
            resource_caches:
                - match_callback: 'navigate'
                  max_age: 365 days
                  max_entries: 200
                  preload_urls:
                      - 'app_index'
            offline_fallback:
                page: 'app_index'

When I test on my local computer (and not my phone), if I use the Chrome network tab to turn off the network, it seems to work sometimes. But not if I actually turn my wifi off.

Source is at https://github.com/survos-sites/pokemon

[tacman]

@Spomky any suggestions? I'm hoping to deploy an audio-tour site by next week, an exhibition is opening so there's a drop-dead date of a week from today, and running offline would be great, because the exhibition is in a tiny community center in Chiapas, Mexico with okay internet in the lobby but poor/no internet in the actual room.