WhatsApp for OnePlus 7T

This is the proximity sensor falsely triggering, so the 7T thinks the phone is at your ear and routes the audio to the earpiece while blanking the screen. First make sure no screen protector or case overlaps the sensor area near the top earpiece, and wipe that area clean. Then reboot the phone, since OxygenOS recalibrates the sensor on restart. You can confirm the sensor is reading correctly with the hidden test menu by dialing *#*#4636#*#* or using OnePlus's built-in diagnostics, and if it still misreads after a clean reboot, a screen protector or a failing sensor is the likely cause. See how others solved this on Reddit

These freezes are usually caused by OxygenOS aggressive background management or a corrupt app cache rather than the apps themselves. Go to Settings > Apps > WhatsApp > Battery > set it to Don't optimize (the same for Chrome), then clear the WhatsApp cache under Settings > Apps > WhatsApp > Storage > Clear cache. Also make sure OxygenOS is fully updated under Settings > System > System updates, since several 7-series builds shipped freezing bugs that were later patched. See how others solved this on Reddit

The heat and drain usually come from WhatsApp constantly syncing and auto-downloading media in the background rather than a hardware fault. In WhatsApp go to Settings > Storage and data and turn off media auto-download for mobile data, Wi-Fi, and roaming, which cuts most of the background activity. Then check Settings > Battery > Battery usage to confirm WhatsApp is no longer dominating, and clear its cache under Settings > Apps > WhatsApp > Storage > Clear cache if the heat continues. See how others solved this on Reddit

WhatsApp's own backups don't cross between iOS and Android, so an iCloud backup won't restore onto the 7T directly. The supported route is to use a cable with the iPhone and run the official chat-migration flow (WhatsApp's iOS-to-Android transfer, which appears during the 7T's setup when prompted), or use a reputable paid cross-platform transfer tool. For occasional chats only, you can also use WhatsApp > the chat > More > Export chat from the iPhone, though that exports text and limited media rather than full history. Verify your number on the 7T before starting the import. See how others solved this on Reddit

WhatsApp always re-compresses videos sent in a normal chat, which is what causes the quality loss on the 7T regardless of the camera. To keep full resolution, attach the clip as a Document instead of through the gallery: tap the paperclip > Document > Browse to the video file. For everyday sends you can also raise the quality under WhatsApp > Settings > Storage and data > Media upload quality > HD quality. See how others solved this on Reddit

Stuck messages on the 7T are most often a connectivity or background-restriction problem rather than a WhatsApp outage. Make sure WhatsApp can use data freely under Settings > Apps > WhatsApp > Mobile data and Wi-Fi by enabling Background data and Unrestricted data usage, then toggle Airplane mode on and off to refresh the connection. If it continues, clear the WhatsApp cache under Settings > Apps > WhatsApp > Storage, and as a last step reinstall from the Play Store to pull the latest build. See how others solved this on Reddit