WhatsApp for Samsung Galaxy J1 mini prime

The J1 mini prime only has about 768MB-1GB of RAM, so WhatsApp competes with the system for memory and slows down. Close background apps from the Recents button, clear WhatsApp's cache under Settings > Apps > WhatsApp > Storage > Clear Cache, and keep your media small by opening WhatsApp Settings > Data and Storage Usage > Storage Usage to delete large forwarded files. Avoid the newest WhatsApp builds if they no longer support this older Android version, and keep at least 500MB of internal storage free. See how others solved this on Reddit

Incoming call alerts usually fail because battery saving is killing WhatsApp in the background. On this older TouchWiz build, open Settings > Battery, make sure Ultra Power Saving and Power Saving are off, and exclude WhatsApp from any app power management so it can run in the background. Then inside WhatsApp open Settings > Notifications and confirm Call Notifications have a ringtone selected. Also make sure WhatsApp is allowed to draw over other apps (Settings > Apps > gear/More > Draw over other apps) so the full-screen incoming-call banner can appear. See how others solved this on Reddit

Open Settings > Sound and notification > App notifications > WhatsApp and make sure notifications are allowed and not set to Priority-only or Block. Then inside WhatsApp go to Settings > Notifications and set Popup Notification (under Message Notifications) to 'Always show popup' so a banner appears, with High Priority Notifications turned on. If popups still don't show, force stop WhatsApp from Settings > Apps > WhatsApp and reopen it to refresh the notification. See how others solved this on Reddit

On low-RAM phones like this one, Samsung's Smart Manager or the system itself swipes notifications away when it kills WhatsApp to free memory. Open Smart Manager and disable any auto-clean or RAM-cleaning feature, and remove WhatsApp from the list of apps it can close. Keeping WhatsApp open in the background (avoid 'Clear all' in Recents) also helps stop its notifications from being cleared. See how others solved this on Reddit

That persistent message means WhatsApp lost its background connection, which is common when power saving cuts off data. Turn off Ultra Power Saving and Power Saving in Settings > Battery, then open Settings > Data Usage, tap WhatsApp and make sure 'Restrict background data' is off so it can sync. Finally reboot the phone so WhatsApp can re-register with Google's push service. See how others solved this on Reddit

Start by confirming WhatsApp's notification switch is on under Settings > Sound and notification > App notifications > WhatsApp, then inside WhatsApp check Settings > Notifications so the message tone is not set to None. Clear the app cache via Settings > Apps > WhatsApp > Storage > Clear Cache and reboot. If alerts still fail, make sure Google Play services is installed and updated, since WhatsApp push relies on it, and reinstalling the latest compatible WhatsApp version often restores notifications on these older devices. See how others solved this on Reddit