Service worker PushEvent not working with microG Services Core 0.2.22.212658

Describe the bug
Hello

I've made a little web app with a frontend where you can subscribe to web push notifications, subscription is then sent to a nodejs server that send notifications back to the client device.

It's working great using Chrome or Brave on regular Samsung OS with Google Apps and Google Services Framework.

My phone is using the last version of microG Lineage OS 18.1 on a LG G5 (h850).
I can receive push notifications from my nodejs server using Firefox.

But using any Chromium based browser, when i subscribe on the frontend the notification sent by my nodejs server is never displayed.

if i go to microG settings > Cloud Messaging > Brave i can see that last message is received when my nodejs server is sending it.
So it's seems that the connection between my nodejs server and Brave browser is working, but client side PushEvent is never triggered.

To make web push notification work, you have to use the Push Service of the browser, so on Chromium based browsers it use an endpoint like https://fcm.googleapis.com/fcm/send/<random-string>, note sure if this is related to my problem as far as i understand microG purpose is to enable FCM Cloud Messaging on Lineage OS.

Thanks if you can help me ;)

Expected behavior
Web push notifications should display using Brave

System
Android Version: [11]
Custom ROM: [microG LineageOS 18.1]

The issue names no repository file or test. Start by reproducing the problem on microG LineageOS 18.1 with a Chromium-based browser, comparing it with Firefox and checking Cloud Messaging delivery; done means the browser receives the message and triggers PushEvent so the notification is displayed.