As noted by AppleInsider, Apple’s support team has responded to complaints that the iOS 15.4 update is causing iPhone batteries to drain too fast.
The article notes that it’s common for an iOS update to cause faster than usual draining of an iPhone battery. And Apple says not to worry.
Here’s the tweet from the Apple support team: It’s normal for your apps and features to need to adjust up to 48 hours after an update.
The team says if unusual battery drain is still an issue after that time to contact Apple.