Make sure that the plugin warns if the wp-crons are disabled. Usually they're disabled like this: https://zeropointdevelopment.com/disabling-wp-cron-in-wordpress/#:~:text=To%20disable%20WP%2DCron%20in,up%20from%20your%20local%20machine.

If they're disabled, the plugin cannot execute the background jobs.