I'm trying to implement a retry http interceptor for Angular 7.

Without import 'zone.js/dist/zone-patch-rxjs'; it works fine but when I add it, I get:

ERROR {"message":"1 errors occurred during unsubscription:\n1) TypeError: Cannot read property 'apply' of null","name":"UnsubscriptionError","errors":[{}]}

This is an example repo to reproduce the issue:

https://stackblitz.com/edit/angular-s3iv5u?file=polyfills.ts

Comment and uncomment the line import 'zone.js/dist/zone-patch-rxjs'; in polyfills.ts to see the error appear and disappear.