WhatsApp for Tecno Pop 8

Open WhatsApp Settings > Notifications and make sure a sound is selected for Message and Group notifications, then go to phone Settings > Apps > WhatsApp > Notifications and confirm the 'Messages' channel is set to 'Make sound and pop on screen' rather than 'Silent'. Android stores its own per-channel sound, so even if WhatsApp's internal tone is set, a silenced system channel will mute everything. Also check that Do Not Disturb and any battery-saver schedule aren't quietly suppressing the alert tone. See how others solved this on Reddit

Updates can reset notification importance, so go to Settings > Apps > WhatsApp > Notifications > Messages and switch the behavior back to 'Urgent (Make sound and pop on screen)'. On the Tecno Pop 8 also open Settings > Apps > Special app access > Display over other apps and ensure WhatsApp is allowed, since heads-up banners need that permission. If banners still don't appear, clearing WhatsApp's cache under Settings > Apps > WhatsApp > Storage often restores them without affecting your chats. See how others solved this on Reddit

When the pop-up toggle disappears, it is usually because the 'Messages' notification channel itself was turned off, so re-enable it under Settings > Apps > WhatsApp > Notifications and the pop-on-screen option will reappear. If it is still missing, clear WhatsApp's data for notifications via Storage and reopen the app so it regenerates the channels. Avoid third-party notification-cleaner apps, which on Tecno's HiOS can strip these channels. See how others solved this on Reddit

This is almost always Tecno's aggressive battery management putting WhatsApp to sleep, so open Settings > Battery and use the background/auto-launch management screen to allow WhatsApp to run in the background. Then in Settings > Apps > WhatsApp > Battery, choose 'Unrestricted' so HiOS stops throttling its notification service. After that, confirm the Messages channel still has sound and pop-on-screen enabled, since the throttling can also have muted it. See how others solved this on Reddit

Work through it in order: enable WhatsApp under Settings > Apps > Special app access > Display over other apps, set its battery usage to Unrestricted, and set the Messages channel to Urgent with pop-on-screen and sound. If notifications still fail, toggle WhatsApp's Messages channel off and back on under Settings > Apps > WhatsApp > Notifications to force Android to rebuild it, and as a last resort reinstall WhatsApp after backing up chats to Google Drive. Keeping WhatsApp updated from the Play Store also matters, as older builds can break notifications on newer HiOS versions. See how others solved this on Reddit