Cron does not start after container reboot

I have a docker container Debian-based where I run some cron processes. The container is launched with the --restart flag.

When the server in which docker is running is restarted, the cron tasks don’t start. They are up again after the shell command cron start is typed.

I was looking to tackle this issue, so that cron is automatically started after every server reboot.

Source: StackOverflow