On Windows 8.1/10 Endpoints you find that after a Power Down/Power On, neither the Computer Shutdown or Startup sections within EM Policy have been triggered.
This issue will occur if the Endpoint has been configured with the Fast Startup option enabled.
You can check if this option is enabled on Windows 10 by navigating to the section below via Control Panel:
With Fast Startup enabled, the Endpoint enters a hibernated state rather than performing a usual shutdown.
On starting up the same services will be running so EmCoreService.exe will not start again (The PID will be the same as prior to "shutdown") hence Environment Manager will get no shutdown or start-up trigger events.