Resolution:
In many cases, users deploy a hook xml file in the resources/shared/hook directory, but sometimes, the hook is not executed because the Engine is running services using Grid Libraries.

The idea of using a Grid Library is to create an isolated running environment without interference of resouces except ones explicitly requested by the Grid Library. Hook XML files under the resources/shared/hook directory will not be used when an Engine is running with Grid Libraries loaded. Only the hooks in the Grid Libraries will be used.