WhatsApp for Oppo Reno 6

ColorOS aggressively freezes background apps to save battery, which kills WhatsApp's connection. Go to Settings > Battery > App battery management (or Power Saver), find WhatsApp and turn off any restriction so it can run in the background and auto-launch. Then open the recent apps screen, drag WhatsApp's card down (or tap the menu on its card) to lock it so ColorOS won't clear it. Finally confirm Settings > Notification & status bar > Manage notifications > WhatsApp has Allow notifications and lock-screen banners enabled. See how others solved this on Reddit

This is caused by ColorOS restricting WhatsApp's wake and overlay permissions. Go to Settings > Apps > App management > WhatsApp > Display over other apps and enable it, then in the same app's Battery usage / Power consumption settings allow background activity and auto-launch. Finally, in WhatsApp itself tap Settings > Notifications and make sure incoming call notifications are on. See how others solved this on Reddit

This usually happens when ColorOS has paused WhatsApp's background sync or the app's cache is corrupted. First disable battery restrictions for WhatsApp under Settings > Battery > App battery management, then clear the cache via Settings > Apps > App management > WhatsApp > Storage usage > Clear cache (this is safe and won't delete chats). If it persists, update WhatsApp from the Play Store, since older builds had a list-refresh bug. See how others solved this on Reddit

WhatsApp compresses images heavily and ColorOS can block its storage access mid-transfer. Make sure Settings > Apps > App management > WhatsApp > Permissions has Photos and media/Files allowed, then in WhatsApp tap the attach (paperclip) icon and send the picture as a Document instead of through the photo picker to keep full quality. If sending fails entirely, clear WhatsApp's cache and confirm you have free storage space. See how others solved this on Reddit

The official iOS-to-Android transfer needs the two phones connected by a USB-C-to-Lightning cable during a fresh Android setup, because iCloud backups can't be read by Android. On the Reno 6's initial setup choose Move data from iPhone, install WhatsApp when prompted, and follow the Move chats step that uses the cable. If your phone is already set up, you'll have to factory reset to redo setup, or use a paid third-party transfer tool, since there is no in-app iCloud-to-Google-Drive option. See how others solved this on Reddit

On older 2G/3G networks data is suspended during a voice call, and ColorOS also limits background apps mid-call. Turn on VoLTE under Settings > Mobile network / SIM so mobile data stays active while you're on a call, then go to Settings > Apps > App management > WhatsApp > Display over other apps and enable it so call banners can appear over the dialer. Locking WhatsApp and Maps in the recent apps tray also stops ColorOS from suspending them during the call. See how others solved this on Reddit