My Ionic info:
cli packages: (/usr/lib/node_modules) @ionic/cli-utils : 1.9.2 ionic (Ionic CLI) : 3.9.2 global packages: Cordova CLI : 7.0.1 local pack
i faced this problem before ,try this instead of ionic serve :
npm run ionic:serve
The only thing that works for me, after check out node/npm installs, was:
Enable "update on reload" on chrome://inspect/#service-workers.