WhatsApp push notifications get disabled permanently after reset of iOS settings.
after reset of settings in iOS by clicking Settings > General > Transfer or Reset Phone > Reset, the push notifications get disabled for WhatsApp. Subsequently notifications does not get reactivated even after opening WhatsApp, which does not show prompt for allowing push notifications as it did upon first install of the app.
The WhatsApp app too don't show up at all in list on ios settings > Notifications, till the WhatsApp app is uninstalled and reinstalled.
The notification settings within the WhatsApp display status message that notifications are disabled in iOS Settings. However this status is false as nothing is disabled on iOS. Instead the WhatsApp should initiate the prompt asking enabling of push notifications, which it does not.