Hassio supervisor does not start without internet

Hassio is supposed to work without an internet connection and it does after the first boot. After the initial boot everything works and I am able to access the UI. If I unplug the raspberry pi from the internet everything still works until I reboot the raspberry pi. After the reboot I can see that the hassio-supervisor docker container is not there. It’s like it’s gone completely. If I connect the respberry pi back to the internet I can use a command to download the supervisor docker image which then installs it and I can access the UI again. Basically the issue is that the supervisor does not start when there is no internet connection and then I cannot access the UI. Has anyone run into this issue or can offer some guidance?

Where does it say that?

Home Assistant OS (the term hassio has been deprecated for around 6 months) has a hardcoded NTP server and if the server can’t be reached the supervisor won’t start.