If your site is a progressive web app (PWA), there's a Service Worker installed. The additional time taken to initiate the service worker and dispatch the first fetch event is non-zero, so this timer tracks how long it takes.
If your site is a progressive web app (PWA), there's a Service Worker installed. The additional time taken to initiate the service worker and dispatch the first fetch event is non-zero, so this timer tracks how long it takes.