Using the latest Edge version from the Play Store I am unable to receive push notifications. The first notification once you allow the permission is received just fine but further notifications are not received. I confirmed that it's happening here on the official forums.

A simple but poweful tool for xF2.2! This addon allows you to make your board more interactive. An AJAX call is checking every x seconds (specified by admin) and auto-refreshes both notifications counter on your page (alerts and new conversation messages). :) It is not compatible with xF2.0...

Description: Customize default push notifications notice with some extra features and lots of customization options in style properties. Features: default or floating (on the left bottom side) push notification notice two styles for floating push notification buttons fully customizable...