Some iPhone users took to Twitter to complain about battery drain after installing iOS 15.4. Apple Support responded to these customers by tweeting that it's normal for some apps and features to adjust for "up to 48 hours after an update."
The update also fixes a bug that causes braille devices to become unresponsive when navigating text or showing an alert, as well as a bug that causes some iPhone hearing devices to lose connection in some third-party apps.
Apple's iOS 15.4 was released on March 15, and the update included the ability to unlock your iPhone using Face ID while wearing a mask,, and other features.
For more Apple news, check out, and .