WhatsApp for Samsung Galaxy S8

On your old phone, open WhatsApp, go to Settings > Chats > Chat backup and back up to Google Drive using the same Google account you'll use on the S8. After signing into WhatsApp on the S8 with the same phone number, it will detect the backup and offer to restore it during setup. Since both are Android, you can also restore from a local backup by copying the old WhatsApp/Databases folder to the same location in the S8's internal storage before installing the app, then choosing Restore when prompted. See how others solved this on Reddit

Yes, use Samsung's Secure Folder for the second account. Go to Settings > Biometrics and security > Secure Folder, set it up, then install WhatsApp inside the Secure Folder from the Play Store and register it with your second number. The Secure Folder runs a separate, sandboxed copy so both accounts work independently. Note that notifications for the Secure Folder app can be delayed or hidden while the folder is locked, so you may need to keep it unlocked for reliable alerts. See how others solved this on Reddit

One UI's aggressive battery management is usually putting WhatsApp to sleep in the background. Go to Settings > Apps > WhatsApp > Battery and set it to Unrestricted, then open Settings > Device care > Battery and make sure WhatsApp is not listed under Sleeping or Deep sleeping apps (remove it if it is, and add it to apps that won't be put to sleep). Also confirm notifications are enabled under Settings > Apps > WhatsApp > Notifications. See how others solved this on Reddit

The S8 launched on Android 7 and tops out at Android 9, which is well past Samsung's security update window, so it carries some risk for any sensitive app. WhatsApp still functions for now, but the app periodically raises its minimum Android version, so be prepared for it to eventually stop receiving updates on this device. If you keep using it, install WhatsApp only from the Play Store and avoid sideloaded APKs to reduce the security exposure. See how others solved this on Reddit

First check for a Google Drive backup tied to your account under WhatsApp > Settings > Chats > Chat backup, since reinstalling WhatsApp with the same number can restore it. If there's no cloud backup, look in the phone's internal storage under WhatsApp/Databases for dated msgstore.db.crypt files, which WhatsApp can restore from if the most recent one is placed correctly before a fresh install. Old encrypted local backups can only be decrypted with the same phone number, so avoid overwriting them and don't run random recovery tools that may corrupt the files. See how others solved this on Reddit

Modern WhatsApp and One UI both support inline replies natively, so you no longer need any beta workaround. When a message arrives, pull down the notification shade and tap Reply on the WhatsApp notification to type and send without opening the app. If you don't see it, make sure notifications are enabled under Settings > Apps > WhatsApp > Notifications. See how others solved this on Reddit