Apple has issued an update to iOS 12, which fixes several bugs that have plagued iPhone XS and XS Max users since the phones were released.
iOS 12.0.1 is available on 3uTools now, iPhone XS and XS Max users are recommended to install this version.
Step 1 Connect your device to PC with USB cable, and launch 3uTools.
Step 2 Navigate to Flash & JB → Easy Flash, select firmware iOS 12.0.1 and click Flash. ( If you want to save the data, please click the checkbox "Retain User's Data While Flashing")
Step 3 Keep a good connection and internet while flashing, wait patiently for around 5 to 10 minutes. Your device will be upgraded to iOS 12.0.1 after reboot.