WhatsApp for Poco X4 Pro

MIUI/HyperOS often hides the WhatsApp media folder, so first make sure media visibility is on: open WhatsApp, tap the three dots, Settings, Chats, and enable Media visibility. If photos still won't appear, go to Settings, Apps, Manage apps, WhatsApp, Permissions, and confirm Files and media access is granted. Then open the Files app, enable 'Show hidden files', and check that there isn't a .nomedia file inside the WhatsApp Images folder, since that stops Gallery from re-indexing those photos. See how others solved this on Reddit

This is almost always MIUI/HyperOS battery management killing WhatsApp's background connection. Go to Settings, Apps, Manage apps, WhatsApp, tap Battery saver and set it to 'No restrictions', then enable Autostart on the same app page. Next open Recent apps, swipe down on the WhatsApp card (or long-press it) and tap the lock icon so the system can't clear it. This keeps messages arriving without needing a daily reboot. See how others solved this on Reddit

Check both WhatsApp and the system settings: in Settings, Apps, Manage apps, WhatsApp, Notifications, make sure notifications are enabled and that the Messages and Group categories are turned on. Then go to Settings, Notifications & Control Center, Lock screen notifications, and confirm WhatsApp is allowed to show on the lock screen; if you only see a dot with no text, switch the lock-screen format to show notification content. See how others solved this on Reddit

Start by clearing only the cache, which doesn't touch your chats: Settings, Apps, Manage apps, WhatsApp, Clear data, then choose Clear cache and reopen the app. If it still crashes, update WhatsApp from the Play Store (or reinstall the latest version from whatsapp.com) and make sure HyperOS is current via Settings, About phone, check for updates, since an outdated app or system version is the usual cause. See how others solved this on Reddit

Grant WhatsApp contacts access in Settings, Apps, Manage apps, WhatsApp, Permissions, Contacts, and set it to Allow. Then open WhatsApp, go to the chats screen, tap the new-chat icon and pull down to refresh the contacts list. Also make sure your contacts are saved to your Google account rather than just the SIM, and that numbers are stored in full international format (with country code), since that is what WhatsApp matches against. See how others solved this on Reddit

HyperOS blocks the full-screen call interface unless you allow it: go to Settings, Apps, Manage apps, WhatsApp, Permissions, and enable 'Display pop-up windows while running in the background'. On the same WhatsApp app page, turn on Autostart and set Battery saver to 'No restrictions' so incoming calls can wake the screen and ring on the lock screen instead of silently going to a missed call. See how others solved this on Reddit