WhatsApp for Samsung Galaxy A8 (2018)

First clear the app's local data: Settings > Apps > Contacts > Storage > Clear cache, then Clear data (your contacts are safe in your Google account). Do the same for the hidden system app: Settings > Apps, tap the three-dot menu > Show system apps, open Contacts Storage and clear its cache, then restart the phone. If names are still missing, open Contacts > tap the menu > Settings, and under the contacts-to-display/source option make sure your Google account is included. Finally confirm sync is on: Settings > Accounts and backup > Manage accounts > your Google account > Sync account > turn on Contacts. See how others solved this on Reddit

RCS support on the A8 (2018) depends on your carrier, and many networks only enable it through Google Messages rather than Samsung Messages. The simplest fix is to install Google Messages from the Play Store, set it as your default SMS app under Settings > Apps > Choose default apps > SMS app, then open it and turn on chat features under its Settings > RCS chats. If it stays stuck on "Connecting," toggle airplane mode on and off or remove and re-insert the SIM, since RCS registration runs over your mobile data connection. See how others solved this on Reddit

In Android Auto, WhatsApp appears as a messaging/notification integration rather than a standalone app icon, so it must have notification access enabled. Make sure both Android Auto and WhatsApp are updated from the Play Store, then open the Android Auto settings on your phone, tap Notifications, and enable WhatsApp. Note the A8 (2018) runs an older Android version (8.0, upgradable to 9), so also confirm your car or head unit still supports the Android Auto version it can run, since some setups have dropped support for older releases. See how others solved this on Reddit

This is almost always Google Photos still showing cloud-backed copies after you only deleted the local file. Open the Google Photos app, find the image, delete it there too, then empty its trash under Library > Trash. Also check the Gallery app's own Recycle bin (Gallery > menu > Recycle bin) and the Samsung Cloud trash, since deleted items linger in those for up to 30 days before they fully clear. See how others solved this on Reddit

Start by toggling airplane mode on and off, then reseat the SIM card to force the phone to re-register on the network. If there's still no signal, go to Settings > Connections > Mobile networks > Network operators and select your carrier manually, and confirm the correct APN under Settings > Connections > Mobile networks > Access Point Names. If nothing works, reset all connection settings via Settings > General management > Reset > Reset network settings, which clears Wi-Fi, Bluetooth, and mobile-data configs that an update can leave in a bad state. See how others solved this on Reddit