WhatsApp for OnePlus 10T

This lag usually comes from OxygenOS aggressively restricting WhatsApp in the background, plus Bluetooth codec handoff if you're on wireless earbuds. Go to Settings > Apps > App management > WhatsApp > Battery usage and set it to 'Don't restrict', then under Settings > Battery & device care > Battery, make sure WhatsApp isn't being optimized. If the delay only happens on Bluetooth, try changing the codec under Settings > Additional settings > Developer options > Bluetooth Audio Codec to SBC or AAC, since some codecs add latency. See how others solved this on Reddit

Heavy WhatsApp drain on OxygenOS is often caused by it constantly waking in the background to sync. First clear the app cache via Settings > Apps > App management > WhatsApp > Storage usage > Clear cache. Then check whether a stuck call or media sync is the culprit under WhatsApp > Settings > Storage and data > Manage storage. To cut background drain, reduce auto-download (WhatsApp > Settings > Storage and data) and, if the drain is severe, set WhatsApp to 'Optimized' under Settings > Apps > App management > WhatsApp > Battery usage. If it started after an update, reinstalling WhatsApp from the Play Store often clears it. See how others solved this on Reddit

WhatsApp re-encodes every video you send to save data, and the 10T's high-res clips get hit hard by this compression. To keep quality, open WhatsApp > Settings > Storage and data > Media upload quality and switch it to 'HD', or send the clip as a file via the attachment (paperclip) > Document option, which skips compression entirely. For long or large videos, sharing a Google Drive link is the only way to fully preserve the original quality. See how others solved this on Reddit

Stuck or failed video sends are usually a cache or storage permission issue on OxygenOS rather than a network fault. Go to Settings > Apps > App management > WhatsApp > Storage usage and tap Clear cache, then confirm Settings > Apps > App management > WhatsApp > Permissions has Files and media (or Photos and videos) set to allow. If it still hangs, update WhatsApp from the Play Store and restart the phone. See how others solved this on Reddit

This usually happens when WhatsApp lacks phone permission or the Bluetooth call-audio profile isn't enabled for your earbuds. Go to Settings > Apps > App management > WhatsApp > Permissions and enable Phone, then under Settings > Bluetooth, tap the gear icon next to your earbuds and make sure 'Call audio' is turned on. Re-pairing the device and keeping WhatsApp unrestricted in Battery usage usually restores answering from the earbuds. See how others solved this on Reddit

Android-to-iPhone WhatsApp transfer can't use a Google Drive backup, so you need the official 'Move to iOS' path. Install Move to iOS on the 10T, and during the new iPhone's setup choose 'Move Data from Android'; WhatsApp will appear as a transferable item that hands off to the iPhone. Both phones must stay plugged in and on the same Wi-Fi, and your 10T number must match the one you'll verify on the iPhone. See how others solved this on Reddit