Apple’s full release notes for the update are below:
iOS 12.0.1 includes bug fixes and improvements for your iPhone or iPad. This update:
– Fixes an issue where some iPhone XS devices did not immediately charge when connected to a Lightning cable
– Resolves an issue that could cause iPhone XS devices to rejoin a Wi-Fi network at 2.4GHz instead of 5GHz
– Restores the original position of the “.?123” key on the iPad keyboard
– Fixes an issue where subtitles may not appear in some video apps
– Addresses an issue where Bluetooth could become unavailable
For information on the security content of Apple software updates, please visit this website: https://support.apple.com/kb/HT201222