ServiceWorker fails on hard reload (Ctrl-Shift-R) in Chrome

When you shift-reload, the reloaded page will not be controlled by a service worker. This is part of the service worker specification.

This just applies for that next page load. Future page loads (that don't involve shift-reload) will continue to be controlled by a service worker, assuming that the page is in scope of one.

During development you can use, for example, Chrome's Dev-Tools and set that the service workers are updated on each reload:

For further reference you can read Googles Web Essentials on this topic.