WhatsApp for Xiaomi 12

After an update, Xiaomi's battery restrictions usually get re-applied to WhatsApp, which kills it in the background. Go to Settings > Apps > Manage apps > WhatsApp > Battery saver and set it to No restrictions, then go back and turn on Autostart for WhatsApp. If it still misbehaves, open Settings > Apps > Manage apps > WhatsApp > Clear data > Clear cache (use Clear cache, not Clear all data) and reboot. See how others solved this on Reddit

This is almost always a storage-permission issue triggered by the update. Open Settings > Apps > Manage apps > WhatsApp > Permissions and set Files and media (Storage) to Allow. If media still won't save, open WhatsApp > Settings > Storage and data and turn on Media auto-download for mobile data and Wi-Fi. If the problem persists, back up your chats and reinstall WhatsApp so it recreates its media folders. See how others solved this on Reddit

Delayed or missing notifications on Xiaomi come from aggressive battery management cutting WhatsApp's background activity. Go to Settings > Apps > Manage apps > WhatsApp > Battery saver > No restrictions, then turn on Autostart. Next, in Settings > Notifications confirm WhatsApp and its Messages/Group channels are enabled. Finally, open the Recents (multitask) view, long-press the WhatsApp card and tap the lock icon so the system doesn't clear it from memory. See how others solved this on Reddit

The incoming-call banner needs pop-up and lock-screen permissions that MIUI often blocks. Go to Settings > Apps > Manage apps > WhatsApp > Other permissions and enable Display pop-up windows while running in background, Show on lock screen, and Display pop-up window. Then set WhatsApp's Battery saver to No restrictions so the call screen can wake the device in time. See how others solved this on Reddit

When sending breaks right after an update it's usually a stale cache plus revoked permissions. First clear WhatsApp's cache via Settings > Apps > Manage apps > WhatsApp > Clear data > Clear cache, then re-grant Storage and Contacts under Permissions on the same screen. If messages still hang on the clock icon, update WhatsApp to the latest version in the Play Store and toggle Airplane mode off and on to refresh the connection. See how others solved this on Reddit

The photos are still on the phone; the Gallery just isn't indexing the WhatsApp Media folder, often because newer WhatsApp stores media under Android/media instead of the old root path. Open the Files (File Manager) app and browse to Internal storage > Android > media > com.whatsapp > WhatsApp > Media > WhatsApp Images to confirm they're there. To make them reappear in Gallery, delete any .nomedia file inside that folder (a .nomedia file hides media from Gallery — do not create one), then reboot so the Gallery rescans. See how others solved this on Reddit