Notifications and Wi-Fi

The owner receives their alerts in the Lucky Touch Admin app. On Android, these notifications go through Google’s services. One case comes up often: everything arrives on 4G, nothing arrives on Wi-Fi (the venue’s, the office’s, the home network). It is neither the platform nor the phone: it is this Wi-Fi network that blocks the path to Google.

Why

An Android phone keeps a permanent connection to Google’s notification service, mtalk.google.com, on ports TCP 5228 to 5230 (port 443 is used as a fallback, less reliable). This is public information from Google. A Wi-Fi network that closes these ports silences notifications on that network only, even though the platform shows that the notification was sent. The usual causes:

a router or firewall that only lets a few ports out;
a DNS filter (such as AdGuard or Pi-hole) that blocks mtalk.google.com;
a VPN active on the phone or on the network.

Check

On the phone, on Wi-Fi, tap Envoyer une notification de test (Send a test notification).
Switch to 4G (Wi-Fi off) and try again. If the notification arrives on 4G and not on Wi-Fi, it is the Wi-Fi.
On Android, dial in the Phone app:
📍 Type on: Android phone (dial pad)
```
*#*#426#*#*
```
The Google Play services “FCM Diagnostics” screen shows the connection status and the time of the last message. A connection that does not hold on this Wi-Fi confirms the block.

The app says the same thing in words, on the Recevoir les alertes application fermée (Receive alerts when the app is closed) screen, Wi-Fi section, and in the Diagnostic block.

Fix it, on the Wi-Fi router or firewall

Allow outgoing connections to ports TCP 5228, 5229 and 5230;
or allow the name mtalk.google.com in the DNS filter;
or turn off the VPN that cuts this path.

No incoming opening is needed, and nothing needs to change on the venue server.