Apple has released iOS 15.1.1 to prevent dropped calls on iPhone 12 and iPhone 13 models. Or at least that’s how we interpret the release note “improves call drop performance,” which feels like a particularly tortuous way of talking around the problem. On an iPhone 13 Pro, it’s a 384.9 MB download in Settings > General > Software Update.
iOS 15.1.1 has no security entries and seems exclusively focused on the call-dropping problem. If you’ve had trouble with dropped calls on your iPhone 12 or iPhone 13, we recommend updating immediately. Otherwise, it’s worth waiting a few days to see if any unexpected problems crop up.