No notification with F-droid app

### Steps to reproduce

I installed the F-Droid version of Element X and configured UnifiedPush notifications with my Ntfy server, while also disabling battery optimization; however, I received no notifications other than the diagnostic test notification.

I then uninstalled the F-Droid version and installed the Play Store version; notifications work perfectly with both Firebase and my Ntfy server.

### Outcome

#### What did you expect?
A notification should appear when there is a new message.

#### What happened instead?
No notifications on the F-Droid version of Element X, whereas notifications appear with the Play Store version.

### Your phone model

Sony Xperia XZ1 Compact (G8441)

### Operating system version

Android 9

### Application version and app store

element X 26.06.4

### Homeserver

matrix.mial.fr

### Will you send logs?

No

### Are you willing to provide a PR?

No

Start by reproducing the notification failure on the F-Droid build with UnifiedPush and the reported Sony Xperia XZ1 Compact setup, then compare its notification behavior with the Play Store build. Trace the notification delivery path using the issue's configuration; done means new-message notifications arrive reliably on the F-Droid version, not only diagnostic notifications.

Written by the indexing model from the issue text.