CronTab error...start working, but after 2min, 5min sometimes 30min stop

Hi,

I run prestashop on Centos web panel 7 (server: Nginx &Apache version: Apache/2.4.34, PHP version: 7.2.0, MySQL version: 10.1.37-MariaDB).
I have instaled module on prestashop "product import-update".
When I run it manualy it working fast and fine.
When I set up it run autowork(cronjob every hour) it start working, but after 2min, sometimes 5min, sometimes 20min it stopping and don't updating all products, one time it working 1hour 21min and do all job(updating all products).
Why cronjob stopping no't updating all products?
Script creator say med what cronjob on other server working fine.

What i will have set up in server what cronjob work fine?

Thank you