To speed up cronjobs processing, SetCronJob has its own DNS cache. If your domain name's IP has changed but SetCronJob still sends requests to the old IP addresses, you can disable DNS cache as instructed below.
To disable DNS cache for a specific cronjob, click Edit, at the section Connect to your server, uncheck the box DNS cache, and Save changes.
To disable DNS cache for multiple cronjobs, select all the cronjobs, then click With selected: Edit cronjobs, at the section Connect to your server, check the box DNS cache, then uncheck the box below, and Save changes.
If DNS cache is enabled and you want to flush it (clear the DNS cache), visit Cron Jobs > DNS table, click Flush on your domain name. It is recommended to flush the DNS cache after you've changed your domain name's records.