Push Notifications Not Working on iOS or Android

Why This Happens

Both iOS and Android are designed to conserve battery life by suspending background apps. The 3CX app cannot stay connected to your phone system 24/7 in the background — instead, it relies on Apple Push Notification Service (APNs) and Google Firebase Cloud Messaging (FCM) to wake the app when a call arrives.

If these push services are blocked — by notification settings, battery optimization, Focus modes, or manufacturer-specific battery managers — the wake-up signal never reaches the app and the call is missed.

Work through the checklist for your device first. If the issue persists after completing all steps, contact DVGVoIP — we can check push registration status on the server side.

iOS Checklist

1. Notification permissions: Go to Settings › Notifications › 3CX. Ensure Allow Notifications is ON. Also enable Allow Critical Alerts if present — this allows calls to ring even when your phone is silenced.
2. Background App Refresh: Go to Settings › General › Background App Refresh. Ensure it is set to Wi-Fi & Mobile Data (not Off), and that 3CX specifically is toggled on in the list below.
3. Focus / Do Not Disturb: Swipe down Control Centre and check for an active Focus mode (Do Not Disturb, Sleep, Work, etc.). Active Focus modes suppress notifications. Either disable the Focus mode or go to Settings › Focus › your active mode › Apps and add 3CX to the allowed list.
4. Low Power Mode: Go to Settings › Battery and turn off Low Power Mode. When enabled, iOS restricts background refresh, which blocks push delivery.
5. Background activity check: Go to Settings › Battery and review the app activity list. If 3CX shows very low or no background activity, it may be getting restricted by iOS.

Android Checklist

1. Notification permissions: Go to Settings › Apps › 3CX › Notifications. Ensure all notification categories are enabled. Do not leave any channels blocked.
2. Battery optimization: Go to Settings › Battery › Battery Optimization. Switch the filter to All Apps, find 3CX, and set it to Don't optimize. This is the most common cause of missed calls on Android.
3. Manufacturer battery managers (Samsung, Xiaomi, OnePlus, Huawei): Many Android manufacturers run a secondary battery manager that kills background apps independently of the system setting above. Look for options like "Protected Apps," "Never Sleeping Apps," or "App Battery Saver" in your phone's Settings or battery section. Add 3CX to the protected/never-sleeping list. The exact path varies by manufacturer and Android version.
4. Data Saver: Go to Settings › Network › Data Saver (or similar). If Data Saver is enabled, find the option to allow unrestricted background data for 3CX, or disable Data Saver entirely.

In the 3CX App

1. Open the 3CX app and go to Settings › Push Notifications.
2. Confirm that push notifications are enabled within the app.
3. Tap Re-register push (or a similar option). This forces the app to re-register with the 3CX server and Apple/Google push services — often resolves issues after a phone restart or OS update.
4. Make a test call from another extension to verify the issue is resolved.

Network and Firewall

If your device is on a corporate VPN or behind a restrictive firewall, push notifications may be blocked at the network level. Push notifications for 3CX travel through Apple and Google servers, which require outbound access on specific ports:

If you're using a VPN, try disabling it temporarily and test whether calls come through. If they do, your VPN may be blocking the push gateway. Contact your IT administrator to allow the above destinations.

Still Not Working?

If you've completed all the steps above and calls are still being missed, contact DVGVoIP. We can check whether the 3CX server has a valid push registration for your device, and whether push delivery attempts are failing on the server side.

Need Help?

Open a support ticket by emailing support@dvgvoip.com before calling — this helps us resolve your issue faster. Or call (807) 700-7111.