In brief: A few connectivity bugs had slipped through for some Apple users following the hefty update with iOS/iPadOS 13.4. Those have now seemingly been fixed in the latest 13.4.1 patch.
iPhone and iPad users were treated to a host of new and much-awaited features in iOS/iPadOS 13.4; however, the update also introduced a few bugs of its own, which Apple is now addressing in this minor iteration.
For both devices, users should now be able to participate in FaceTime calls with Mac users running OS X El Capitan 10.11.6 and earlier, as well as iPhones and iPads on iOS 9.3.6 and earlier. The patch also includes a fix for Bluetooth, which on iOS/iPadOS 13.4 would crash the Settings app when accessed via the quick actions menu on the home screen.
There's also an additional bug fix for the iPad Pro 12.9-inch (4th generation) and iPad Pro 11-inch (2nd generation) that should now turn on the flashlight when prompted from the Control Center or on the lock screen.
Although no mention of it has been made in the release notes, Apple might also have fixed a glaring VPN issue in this update, discovered in iOS 13.3.1 and still present on iOS 13.4. The vulnerability essentially prevents VPNs from encrypting all internet traffic on an iPhone/iPad by allowing existing connections to bypass the VPN tunnel.
In other update news, Apple followed in Google's footsteps and has silently tweaked its Maps app to include a new food delivery category. The service is now prioritized along with pharmacies and medical facilities on top of in-app searches. The change could be regional but is aimed at helping users with the current lockdown situation.