Internet check on startup fydeos kiosk

Hello,
We’re offering a progressive web application (PWA) that is able to operate fully offline through a service worker cache.
Experimenting with Chrome OS Flex Kiosk and SIgnage we discovered that during a startup of a device that is (temporarily) offline the operating system doesn’t launch te application URL until the internet connection has been restored. It will show a message “Waiting for network connection” even though the application is not dependent on the internet and should be able to start.
Is this behaviour as expected and applicable to all ChromiumOS based products, or will FydeOS Kiosk handle this differently?