How to prevent synch from zero when VM restarts

Hi. Just starting out here, installed on a brand new, clean Debian VM. Bitcoin node starts synching, goes well, but then I had to restart the VM. After a restart the synch starts again from zero %. Restarted a few times to test it out and it always looses the history and begins again.

Is that normal ? Or how can I check/fix the docker / storage setup so that a reboot does not reset everything ?

versions : Debian GNU/Linux 11 (bullseye) running getumbrel/bitcoind:v24.0.1

many thanks