WhatsApp for Vivo

Funtouch OS aggressively suspends background apps to save battery, which delays message delivery and notification sounds. Go to Settings > Battery > High background power consumption and set WhatsApp to "Allow", then open Settings > Apps > Manage apps > WhatsApp > Battery and choose "Don't restrict / No restrictions". Also lock WhatsApp in the Recents (multitask) view by swiping down on its card (or tapping the menu) and tapping the lock icon so the system stops clearing it from memory. See how others solved this on Reddit

Vivo's software (OriginOS on the CN model, Funtouch OS on Global) aggressively kills background apps to save battery, which silences notifications. Open Settings > Battery > High background power consumption, find each affected app and set it to Allow. Then go to Settings > Apps > [app] > Battery usage (or Power consumption management) and choose Allow background activity / No restrictions. Finally, turn off Settings > Battery > power-saving mode and lock important apps in the recent-apps tray (open recents, then tap the lock icon on the app card) so the system stops clearing them. See how others solved this on Reddit

OriginOS aggressively kills background apps, which breaks WhatsApp's call signaling. Go to Settings > Battery > High background power consumption and add WhatsApp (or set its background consumption to Allow/unrestricted), then open Settings > Apps > Manage apps > WhatsApp > enable Autostart. Finally, open the recent-apps screen, hold the WhatsApp card and tap the lock icon so the system stops closing it. After these three changes calls ring reliably again. See how others solved this on Reddit

This is a Funtouch OS privacy setting, not a WhatsApp bug. Go to Settings > Notification & status bar > Lock screen notifications and switch it from Hide notification content to Show all content. Then open Settings > Notification & status bar > Manage notifications > WhatsApp and make sure Allow notifications and the lock-screen/preview toggles are on. Finally, inside WhatsApp go to Settings > Notifications and enable Use high priority notifications so previews appear at the top of the screen. See how others solved this on Reddit

On OriginOS/FunTouch OS you run a second WhatsApp through App Clone rather than installing it twice. Go to Settings > Apps & permissions > App Clone (on some builds it's Settings > App Clone), toggle on WhatsApp, then open the cloned icon and register it with your second number via SMS. If App Clone isn't available, install WhatsApp Business from the Play Store for the second account. See how others solved this on Reddit

OriginOS aggressively freezes WhatsApp in the background, which stops the scheduled Google Drive backup from firing. First run a manual backup: open WhatsApp, go to Settings then Chats then Chat backup and tap Back up. Then in phone Settings open Battery then Background power consumption (App battery management), find WhatsApp and set it to Allow background activity / no restrictions. Finally, open Recents and lock WhatsApp so it isn't cleared. With background activity allowed, the scheduled backup will run. See how others solved this on Reddit

Funtouch OS aggressively freezes background apps, which delays WhatsApp message alerts. Go to Settings > Battery > Background power consumption management, find WhatsApp and set it to 'Allow background activity' (do not let the system optimize it). Then open Settings > Apps > App manager > WhatsApp > Battery and choose 'Don't restrict'. Finally, in Settings > Notifications & status bar > WhatsApp, turn on 'Allow notifications' and 'Lock screen notifications'. See how others solved this on Reddit

OriginOS aggressively closes background apps to save battery, which silences WhatsApp until you reopen it. Open Settings > Battery > Background power consumption management, find WhatsApp and set it to "Allow background activity" (remove restrictions). Then in the Recent Apps tray, pull WhatsApp's card down (or tap the lock icon) to lock it so OriginOS won't clear it from memory. See how others solved this on Reddit

OriginOS aggressively kills background apps to save battery, which stops WhatsApp from pushing alerts. Open Settings > Battery > High background power consumption (or Settings > Apps > App manager > WhatsApp > Battery / Power usage) and set WhatsApp to "Allow background activity" / "No restrictions." Then enable Auto-start for WhatsApp under Settings > Apps > Auto-start management (called Permissions > Autostart on some builds). Finally turn off Battery saver so OriginOS stops force-closing it. See how others solved this on Reddit

OriginOS aggressively kills background apps to save battery, which silences WhatsApp until you reopen it. Go to Settings > Battery > High background power consumption (or Background power consumption management), find WhatsApp and allow it to run in the background. Then open Settings > Apps & permissions > Autostart and enable autostart for WhatsApp. Finally, open the recent apps view and lock WhatsApp's card (tap the lock icon or swipe down on the card) so the system stops clearing it. See how others solved this on Reddit