The change in the latest beta of iOS 12 is building on USB
Restricted Mode which disables the Lightning port of an iOS device
one hour after last being unlocked. The Lightning port could still
be used for charging, but no accessories would be able to function
In the fourth developer beta of iOS 12, a passcode is required any
time a computer or USB accessory is connected.
Before the change, authorities or criminals would have an hour
since last unlock to connect a cracking device, like the GreyKey
box. Now, they don’t have that hour, making it that much more
difficult to brute force a password attempt into a device.