In the ACP, there is a list of tasks. Those tasks run on different schedules at different intervals.
When the cron is processed, it runs through the list of various tasks. It looks at when it's next scheduled to run and if that time is in the past, it runs it and updates the next run time to be at the next time defined by the frequency. If the time has not occurred yet, (meaning the next scheduled run time is still in the future), it skips over it.
I would first confirm your web cron is actually working. I would also confirm if it's making remote calls instead of being done locally that your server's firewall is not rate limiting it or blocking it in any way. (If you're making the request EVERY MINUTE, some firewalls might see that as an attack and try to limit what it can do.)
I would also suggest looking into if your hosting service provides the ability to run cron jobs locally. It's generally MUCH more reliable than externally triggered crons.