WhatsApp for OnePlus 3T

OxygenOS aggressively closes background apps to save battery, which stops WhatsApp from waking the screen. Go to Settings > Battery > Battery optimization, tap the menu (or dropdown) and choose All apps, find WhatsApp and set it to Don't optimize. On the 3T also enable auto-launch under Settings > Battery > Battery optimization > (menu) > Advanced optimization, or via the App launch / Auto-start setting, so WhatsApp can run in the background and wake the display for calls. See how others solved this on Reddit

First make sure the alert slider on the left edge of the phone isn't set to silent or vibrate. Then check WhatsApp's own call notifications: go to Settings > Apps > WhatsApp > Notifications, open the Calls channel and confirm a ringtone is set and sound is enabled. If it's still silent, clear WhatsApp's cache via Settings > Apps > WhatsApp > Storage > Clear cache and restart the phone. See how others solved this on Reddit

WhatsApp's built-in camera uses a low-quality capture path and often stutters on OnePlus hardware. Instead of shooting from inside the chat, take the photo with the stock OnePlus Camera app first, then attach it with the gallery (paperclip) icon in WhatsApp. If the in-app camera keeps freezing, confirm the camera permission under Settings > Apps > WhatsApp > Permissions and clear WhatsApp's cache via Settings > Apps > WhatsApp > Storage > Clear cache. See how others solved this on Reddit

Yes, OxygenOS includes a built-in Parallel Apps feature for dual accounts. Open Settings > Apps & notifications > Parallel Apps (on some versions it's under Settings > Utilities), then toggle on WhatsApp to create a second cloned instance you can register with a different number. Stick to this official clone or WhatsApp Business; third-party modded clones risk getting your account banned. See how others solved this on Reddit

WhatsApp chat backups go to Google Drive via WhatsApp > Settings > Chats > Chat backup, but your media is stored separately. To save the actual image and video files, open Google Photos, enable Backup, then go to Photos settings > Back up device folders and turn on the WhatsApp Images and WhatsApp Video folders. This uploads received media independently of the chat backup. See how others solved this on Reddit

OxygenOS battery management often closes WhatsApp in the background, which drops the linked Web session. Go to Settings > Battery > Battery optimization and set WhatsApp to Don't optimize, then open the recent-apps screen, tap the menu on WhatsApp's card and choose Lock to keep it from being cleared. Make sure the phone stays connected to Wi-Fi or mobile data, and re-link from WhatsApp > Settings > Linked devices if it logs out. See how others solved this on Reddit