https://www.cnbc.com/2018/10/08/iphone-xs-charging-bug-fixed-in-ios-12point0point1.html

Apple just released iOS 12.0.1, which fixes an issue that prevented some new iPhone XS units from properly charging over a Lightning cable. In some cases, iPhone owners plugged their phone in at night only to wake up and find the phone hadn't charged at all.

The update also fixes a couple of other bugs, including one that caused the iPhone XS to reconnect back to a Wi-Fi network on a 2.4GHz frequency instead of on 5GHz. Sometimes that results in slower data, depending on the Wi-Fi network.