First can you please confirm that you don’t have any caching plugins enabled? Caching plugins can interfere with cron jobs because your visitors are not served a live page but a cached version of your page.
If you have a caching plugin enabled, you can choose one of your pages, add an exclusion to your caching plugin’s settings for that page so that it is never cached.
Then you’ll have to manually create a cron job (using Cpanel if you’re on a shared hosting environment or from the terminal if it’s a VPS/dedicated server) that will visit that page every few minutes.
I hope that helps!