Jobs in SAP Agent are getting cancelled automatically.
When you check in Agent log you may see below error messages messages as the reason :
Release : 12.2
Component : ACTION BUILDER
This error is due to the Linux service limitations. That is, Linux service doesn't have enough limit to run the jobs. Hence you can add the following command to push the limit.
1. Open a file named, ini.file, This file will be available in the folder, where you OS is installed. And add the below parameter in the ini.file and save the file.
2. And now restart the AWA services after applying the changes at Operating system side.