Mac OS 10.13.1 and new 1TB G Drive USB-C will not reattach to MacBookPro if the drive is encrypted. When machine is rebooted, drive attaches. Eject drive. Wait. Reconnect drive. Nothing. Reboot machine, drive prompts for password and attaches. Eject. Wait. Reconnect. Drive does not attach. Reboot. Connect drive, attaches. Decrypt drive. Eject. Reconnect. Drive reattaches.
Same behavior using USB 3.0 cable on Mac mini running 10.13.1 (High Sierra)