Issue SSL Cronjob

I have lots of domain on my cyberpanel. Some of them are must have ssl and i used issue ssl button for all of them 3 months ago but today all of them are broken. Chrome gives me private error. So i reissue them now there is no problem.
Question : Is issue ssl button creating cronjob for renew the ssl automatically. if so why my domains ssl has broken after 3 months ? If not, do we have to create a cronjob to renew ssl for each domain ?