WhatsApp for Honor X9c

This is almost always MagicOS battery management suspending WhatsApp in the background. Open Settings > Apps > App launch, find WhatsApp, turn off "Manage automatically" and in the pop-up enable all three options (Auto-launch, Secondary launch, Run in background). Then go to Settings > Apps > Apps > WhatsApp > Notifications and make sure the Calls notification channel is enabled, and inside WhatsApp open Settings > Notifications and turn on "Use high priority notifications" / pop-on-screen. Finally, in Settings > Battery, turn off any aggressive power-saving mode for WhatsApp so call screens can appear when the phone is locked. See how others solved this on Reddit

MagicOS frequently kills WhatsApp's background process or cuts its network on a locked screen, which breaks calls. Go to Settings > Apps > App launch, set WhatsApp to manual management and enable Auto-launch, Secondary launch and Run in background. Check that WhatsApp has both Wi-Fi and mobile data allowed under Settings > Apps > Apps > WhatsApp (Mobile data / data usage). Turn off Power saving / Performance modes that throttle background apps. If calls still drop, the issue is often a restricted Wi-Fi network that blocks VoIP, so test the same call on mobile data to confirm. See how others solved this on Reddit

WhatsApp's official iOS-to-Android transfer relies on Google's "Move to Android" / Android Setup flow and is only certified on certain devices (mainly Samsung and Pixel), so it usually fails on Honor. There is no fully reliable free way to move complete iPhone history to an Honor phone. Your practical options are: keep using the iPhone temporarily while you back up, then just re-verify your number on the Honor and start fresh, or use a reputable paid third-party transfer tool if full history matters. Once you're set up on the Honor, immediately turn on Google Drive backup under WhatsApp > Settings > Chats > Chat backup so future restores are automatic. See how others solved this on Reddit

MagicOS clears apps from memory to save battery, which is the main reason notifications arrive late or not at all. First lock WhatsApp in the recent apps screen: open recents, then swipe down on the WhatsApp card (or tap the lock icon) to pin it so it won't be cleared. Then open Settings > Apps > App launch, switch WhatsApp from automatic to manual, and enable Auto-launch, Secondary launch and Run in background. Setting the app's notifications to high priority under Settings > Apps > Apps > WhatsApp > Notifications helps them arrive instantly. See how others solved this on Reddit

Android Auto only surfaces messaging-app calls when the apps are allowed to run unrestricted and their notifications are fully granted, which Honor's battery management tends to block. In Settings > Apps > App launch, set both WhatsApp and Signal to manual with all launch options enabled, and confirm their notifications are on under Settings > Apps > Apps > [app] > Notifications. In the Android Auto settings, make sure notifications for those apps are enabled. Note that Android Auto is designed to show incoming-call notifications but won't let you place or fully manage WhatsApp/Signal calls from the car screen. See how others solved this on Reddit