WhatsApp for OnePlus 3

The OnePlus Watch 3 uses a dual-engine setup (Wear OS plus a power-saving RTOS) and there is no standalone WhatsApp app for it, so the watch can only mirror notifications coming from your phone. Pair the watch in the OHealth app, then in OHealth grant it Notification access when prompted. Next, on the phone open Settings > Apps > WhatsApp > Notifications and confirm notifications are enabled, since the watch can only relay what the phone is allowed to show. See how others solved this on Reddit

This usually follows a phone or watch update that resets the notification link to OHealth. On the phone, re-confirm OHealth still has Notification access (Settings > Apps > Special app access > Notification access), then in OHealth's app/notification list toggle WhatsApp off and back on. Set OHealth to Unrestricted battery under Settings > Apps > OHealth > Battery so background syncing isn't killed. If toggling alone doesn't help, unpair and re-pair the watch over Bluetooth to rebuild the link. See how others solved this on Reddit

Incoming WhatsApp calls use a separate high-priority notification channel that aggressive battery saving on the phone often blocks. On the phone open Settings > Apps > WhatsApp > Notifications and make sure the Calls channel is enabled, then set both WhatsApp and OHealth to Unrestricted battery (Settings > Apps > [app] > Battery). On OnePlus phones, background limits in OxygenOS are the most common reason call alerts never reach the watch. See how others solved this on Reddit

Both apps deliver call alerts through a high-priority channel that the phone must forward in real time. Open Settings > Apps > WhatsApp (and Signal) > Notifications and enable the call-specific channels, then confirm both apps are checked in OHealth's notification list. Finally, set OHealth to Unrestricted battery (Settings > Apps > OHealth > Battery) so the persistent watch connection isn't dropped while the screen is off. See how others solved this on Reddit

On non-OnePlus phones (for example a vivo X200 Pro), the manufacturer's own battery and auto-start management often suppresses the call notification before it reaches the watch. On that phone, enable the WhatsApp Calls channel under Settings > Apps > WhatsApp > Notifications, add WhatsApp and the OHealth companion app to the phone's auto-start / protected-apps list (on vivo this is in the battery or app-management settings), and set both to Unrestricted battery so the alert fires before the system shuts down background apps. See how others solved this on Reddit

Because the Watch 3 only mirrors phone notifications, every WhatsApp permission lives on the phone, not the watch. Make sure WhatsApp is enabled in OHealth's notification list, and check that the phone isn't in Do Not Disturb, because a phone-side DND or notification block can stop alerts from ever being forwarded. Keep WhatsApp and OHealth on Unrestricted battery, and after any firmware update re-check these toggles, which resolves most reported glitches. See how others solved this on Reddit